AIM:To compare the 12-month outcomes of visual performance and patient satisfaction of a higherorder aspheric monofocal intraocular lens(IOL)and a conventional monofocal IOL.METHODS:Prospective,randomized,comparative,...AIM:To compare the 12-month outcomes of visual performance and patient satisfaction of a higherorder aspheric monofocal intraocular lens(IOL)and a conventional monofocal IOL.METHODS:Prospective,randomized,comparative,double-blinded study including 22 patients who underwent bilateral cataract surgery with implantation of the Tecnis Eyhance ICB00 IOL in one eye(ICB00 group)and the Tecnis ZCB00 IOL in the fellow eye(ZCB00 group).Uncorrected distance(UDVA),corrected distance(CDVA),uncorrected intermediate(UIVA),distance-corrected intermediate(DCIVA),uncorrected near(UNVA),and distance-corrected near visual acuities(DCNVA)were evaluated during a 12-month follow-up.Contrast sensitivity,defocus curves,and reading text size were also evaluated.Patient satisfaction was assessed with a questionnaire at the 6-month postoperative visit.RESULTS:Mean postoperative logMAR UDVA was 0.01±0.12 and-0.02±0.10 in ICB00 and ZCB00 groups,respectively(P=0.37).Mean logMAR UIVA was 0.32±0.19 and 0.45±0.16 in ICB00 and ZCB00 groups,respectively(P=0.010).Differences between groups in UNVA did not reach statistical significance(P=0.16).The intermediate reading acuity at 66 cm(P=0.02)and 80 cm(P=0.04)was significantly better in the ICB00 group.Postoperative contrast sensitivity results did not differ significantly between groups(P>0.05).Patients reported high overall satisfaction,with 62%of patients using spectacles for reading in everyday life.CONCLUSION:The eyes of patients implanted with the enhanced monofocal IOL evaluated have significantly better visual acuity for intermediate distances with the same contrast sensitivity as a conventional monofocal IOL.展开更多
AIM:To assess whether the implantation of a posterior chamber phakic intraocular lens produces changes in optical coherence tomography(OCT)measurements of macular thickness(MT)and two parameters that define the struct...AIM:To assess whether the implantation of a posterior chamber phakic intraocular lens produces changes in optical coherence tomography(OCT)measurements of macular thickness(MT)and two parameters that define the structure of the optic nerve,the peripapillary nerve fiber layer(RNFL)and the Bruch’s membrane opening-minimum rim width(BMO-MRW).METHODS:This nonrandomized prospective pre-post study included 86 eyes of 48 patients(age,20-47y;axial length:23.10-28.95 mm)scheduled for myopia or myopic astigmatism correction with implantation of the implantable collamer lens(ICL).Eyes with glaucoma or any other ocular disease that could alter OCT results were excluded.RNFL,BMO-MRW and MT were measured preoperatively,and at 1 and 6mo after surgery using spectral-domain OCT.Changes between preoperative and postoperative values were evaluated.RESULTS:There was a significant increase in BMOMRW at 1mo(mean change:3.48±15.07μm,P=0.041).No significant changes were found during the rest of followup(1-6mo postop.,P=0.623).There was also a significant increase in RNFL thickness at 1mo af ter surger y(1.45±2.18μm,P<0.001),but with a significant reduction from 1 to 6mo postoperatively(P=0.002).Regarding MT,it increased significantly at 1mo(2.46±3.76μm,P<0.001),with a significant decrease afterwards(P=0.048).Measurements of the three parameters at 6mo were slightly superior to preoperative values(P<0.01).CONCLUSION:Minimal changes are induced in BMOMRW,RNFL and MT after ICL implantation in healthy eyes,confirming the safety of the surgical procedure regarding the structure of the optic nerve head and the macula,and indicating that this phakic intraocular lens seems to have a slight impact on OCT measurements.展开更多
AIM:To investigate the prevalence of visual impairment(VI)and provide an estimation of uncorrected refractive errors in school-aged children,conducted by optometry students as a community service.METHODS:The study was...AIM:To investigate the prevalence of visual impairment(VI)and provide an estimation of uncorrected refractive errors in school-aged children,conducted by optometry students as a community service.METHODS:The study was cross-sectional.Totally 3343 participants were included in the study.The initial examination involved assessing the uncorrected distance visual acuity(UDVA)and visual acuity(VA)while using a+2.00 D lens.The inclusion criteria for a subsequent comprehensive cycloplegic eye examination,performed by an optometrist,were as follows:a UDVA<0.6 decimal(0.20 logMAR)and/or a VA with+2.00 D≥0.8 decimal(0.96 logMAR).RESULTS:The sample had a mean age of 10.92±2.13y(range 4 to 17y),and 51.3%of the children were female(n=1715).The majority of the children(89.7%)fell within the age range of 8 to 14y.Among the ethnic groups,the highest representation was from the Luhya group(60.6%)followed by Luo(20.4%).Mean logMAR UDVA choosing the best eye for each student was 0.29±0.17(range 1.70 to 0.22).Out of the total,246 participants(7.4%)had a full eye examination.The estimated prevalence of myopia(defined as spherical equivalent≤-0.5 D)was found to be 1.45%of the total sample.While around 0.18%of the total sample had hyperopia value exceeding+1.75 D.Refractive astigmatism(cil<-0.75 D)was found in 0.21%(7/3343)of the children.The VI prevalence was 1.26%of the total sample.Among our cases of VI,76.2%could be attributed to uncorrected refractive error.Amblyopia was detected in 0.66%(22/3343)of the screened children.There was no statistically significant correlation observed between age or gender and refractive values.CONCLUSION:The primary cause of VI is determined to be uncorrected refractive errors,with myopia being the most prevalent refractive error observed.These findings underscore the significance of early identification and correction of refractive errors in school-aged children as a means to alleviate the impact of VI.展开更多
AIM:To evaluate the reliability of measurements of corneal changes with accommodation in healthy eyes using a Scheimpflug imaging-based system and how these measurements distribute in the normal population.METHODS:Pro...AIM:To evaluate the reliability of measurements of corneal changes with accommodation in healthy eyes using a Scheimpflug imaging-based system and how these measurements distribute in the normal population.METHODS:Prospective,non-randomized,comparative study including 27 healthy subjects(54 eyes),including emmetropia(13 eyes),myopia(17 eyes),hyperopia(4 eyes)and astigmatism(20 eyes)groups.In all cases,a complete eye examination was performed,including the analysis of corneal changes with different accommodative stimuli(+2.00,0.00 and-3.00 D)using the Pentacam AXL system.The investigation was structured in 2 phases:repeatability analysis and characterization of accommodation-related corneal changes in healthy populations.RESULTS:In the repeatability analysis,the index of height asymmetry(IHA)showed the greatest variability with the three accommodative stimuli,being the results for the rest of parameters acceptable.The group of emmetropes showed significant differences with accommodative changes in the position of maximum keratometry(Kmax;P<0.05),whereas in the astigmatism group,significant changes were not only observed in the position of Kmax,but also in minimum corneal thickness(MCT),corneal spherical aberration,and total and low order aberration root mean square(all P<0.05).Likewise,a significant difference was found in the displacement of the X position of Kmax with+2.00 D and-3.00 D in the myopia group(P=0.033)as well as in changes with+2.00 D and-3.00 D in the magnitude of the position vector of Kmax in the emmetropia group(P<0.05).No significant changes were found between accommodative stimuli in the displacement of coordinates of MCT(P≥0.109).CONCLUSION:The position of Kmax and MCT in healthy corneas can change significantly when presenting different accommodative stimuli using the accommodation mode of the Pentacam system,with different trends in these accommodation-related corneal changes between refractive errors.Likewise,the consistency of the measurements obtained with Scheimpflug has been confirmed.展开更多
Under high relative humidity(RH)conditions,the release of volatile components(such as acetate)has a significant impact on the aerosol hygroscopicity.In this work,one surface plasmon resonance microscopy(SPRM)measureme...Under high relative humidity(RH)conditions,the release of volatile components(such as acetate)has a significant impact on the aerosol hygroscopicity.In this work,one surface plasmon resonance microscopy(SPRM)measurement system was introduced to determine the hygroscopic growth factors(GFs)of three acetate aerosols separately or mixed with glucose at different RHs.For Ca(CH_(3)COO)_(2) or Mg(CH_(3)COO)_(2) aerosols,the hygroscopic growth trend of each time was lower than that of the previous time in three cyclic humidification from 70% RH to 90% RH,which may be due to the volatility of acetic acid leading to the formation of insoluble hydroxide(Ca(OH)_(2) or Mg(OH)_(2))under high RH conditions.Then the third calculated GF(using the Zdanovskii-Stokes-Robinson method)for Ca(CH_(3)COO)_(2) or Mg(CH_(3)COO)_(2) in bicomponent aerosols with 1:1 mass ratio were 3.20% or 5.33% lower than that of the first calculated GF at 90% RH.The calculated results also showed that the hygroscopicity change of bicomponent aerosol was negatively correlated with glucose content,especially when the mass ratio of Mg(CH_(3)COO)_(2) to glucose was 1:2,the GF at 90% RH only decreased by4.67% after three cyclic humidification.Inductively coupled plasma atomic emission spectrum(ICP-AES)based measurements also indicated that the changes of Mg^(2+)concentration in bicomponent was lower than that of the single-component.The results of this study reveal thatduring the efflorescence transitions of atmospheric nanoparticles,the organic acids diffusion rate may be inhibited by the coating effect of neutral organic components,and the particles aging cycle will be prolonged.展开更多
The Chinese-Russian Workshop on Biophotonics and Biomedical Optics 2023 was held online twice on 18–21 September and 25–26 September 2023.The bilateral workshop brought together both Russian and Chinese scientists,e...The Chinese-Russian Workshop on Biophotonics and Biomedical Optics 2023 was held online twice on 18–21 September and 25–26 September 2023.The bilateral workshop brought together both Russian and Chinese scientists,engineers,and clinical researchers from a variety of disciplines engaged in applying optical science,photonics,and imaging technologies to problems in biology and medicine.During the workshops,two plenary lectures and twenty invited presentations were presented.This special issue selects some papers from both Russian and Chinese sides,consisting of one review and seven original research articles.展开更多
Optical data storage(ODS)is a low-cost and high-durability counterpart of traditional electronic or mag-netic storage.As a means of enhancing ODS capacity,the multiple recording layer(MRL)method is more promising than...Optical data storage(ODS)is a low-cost and high-durability counterpart of traditional electronic or mag-netic storage.As a means of enhancing ODS capacity,the multiple recording layer(MRL)method is more promising than other approaches such as reducing the recording volume and multiplexing technology.However,the architecture of current MRLs is identical to that of recording data into physical layers with rigid space,which leads to either severe interlayer crosstalk or finite recording layers constrained by the short working distances of the objectives.Here,we propose the concept of hybrid-layer ODS,which can record optical information into a physical layer and multiple virtual layers by using high-orthogonality random meta-channels.In the virtual layer,32 images are experimentally reconstructed through holog-raphy,where their holographic phases are encoded into 16 printed images and complementary images in the physical layer,yielding a capacity of 2.5 Tbit cm^(-3).A higher capacity is achievable with more virtual layers,suggesting hybrid-layer ODS as a possible candidate for next-generation ODS.展开更多
AIM： To determine the presence of symptomatic accommodative and non-strabismic binocular dysfunctions （A.sBD） in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： ...AIM： To determine the presence of symptomatic accommodative and non-strabismic binocular dysfunctions （A.sBD） in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and one VDU users, aged between 20 to 34y, initially participated in the study. This study excluded contact-lens wearers and subjects who had undergone refractive surgery or had any systemic or ocular disease. First, subjects were asked about the type and nature of eye symptoms they experienced during VDU use. Then, a thorough eye examination excluded those subjects with a significant uncorrected refractive error or other problem, such as ocular motility disorders, vertical deviation, strabismus and eye diseases. Finally, the remaining participants underwent an exhaustive assessment of their accommodative and binocular vision status. RESULTS： Eighty-nine VDU users （46 females and 43 males） were included in this study. They used flat-panel displays for an average of 5±1.9h a day. Twenty subjects presented A.sBD （22.5%）. Convergence excess was the most frequent non-strabismic binocular dysfunction （9 subjects）, followed by fusional vergence dysfunction （3 subjects） and convergence insufficiency （2 subjects）. Within the accommodative dysfunctions, accommodative excess was the most common （4 subjects）, followed by accommodative insufficiency （2 subjects）. Moderate to severe eye symptoms were found in 13 subjects with ANSBD. CONCLUSION： Significant eye symptoms in VDU users with accommodative and/or non-strabismic binocular dysfunctions often occur and should not be underestimated; therefore, an appropriate evaluation of accommodative and binocular vision status is more important for this population,展开更多
AIM:To evaluate the accuracy of spherical equivalent(SE) estimates of a double-pass system and to compare it with retinoscopy,subjective refraction and a table mounted autorefractor.METHODS:Non-cycloplegic refraction ...AIM:To evaluate the accuracy of spherical equivalent(SE) estimates of a double-pass system and to compare it with retinoscopy,subjective refraction and a table mounted autorefractor.METHODS:Non-cycloplegic refraction was performed on 125 eyes of 65 healthy adults(age 23.5±3.0 years) from October 2010 to January 2011 using retinoscopy,subjective refraction,autorefraction(Auto kerato refractometer TOPCON KR-8100,Japan) and a double pass system(Optical Quality Analysis System,OQAS,Visiometrics S.L.,Spain).Nine consecutive measurements with the double-pass system were performed on a subgroup of 22 eyes to assess repeatability.To evaluate the trueness of the OQAS instrument,the SE laboratory bias between the double pass system and the other techniques was calculated.RESULTS:The SE mean coefficient of repeatability obtained was 0.22D.Significant correlations could be established between the OQAS and the SE obtained with retinoscopy(r=0.956,P【0.001),subjective refraction(r=0.955,P【0.001) and autorefraction(r=0.957,P【0.001).The differences in SE between the double-pass system and the other techniques were significant(P【0.001),but lacked clinical relevance except for retinoscopy;Retinoscopy gave more hyperopic values than the double-pass system-0.51±0.50D as well as the subjective refraction-0.23±0.50D;More myopic values were achieved by means of autorefraction 0.24±0.49D. CONCLUSION:The double-pass system provides accurate and reliable estimates of the SE that can be used for clinical studies.This technique can determine the correct focus position to assess the ocular optical quality.However,it has a relatively small measuring range in comparison with autorefractors(-8.00 to +5.00D),and requires prior information on the refractive state of the patient.展开更多
AIM:To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis(LASIK)in eyes with myopic astigmatism using wavefront-guided(WFG)and wavefront-optimized(WFO)ablation pr...AIM:To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis(LASIK)in eyes with myopic astigmatism using wavefront-guided(WFG)and wavefront-optimized(WFO)ablation profiles.METHODS:Prospective study included 221 eyes undergoing LASIK:99 and 122 eyes with low and moderate myopic astigmatism(low and moderate myopia groups).Two subgroups were differentiated in each group according to the ablation profile:WFG subgroup,109 eyes(45/64,low/moderate myopia groups)treated using the Advanced Custom Vue platform(Abbott Medical Optics Inc.),and WFO subgroup,112 eyes(54/58,low/moderate myopia groups)treated using the EX-500 platform(Alcon).Clinical outcomes were evaluated during a 6-month follow-up,including a vector analysis of astigmatic changes.RESULTS:Significantly better postoperative uncorrected visual acuity and efficacy index was found in the WFG subgroups of each group(P≤0.041).Postoperative spherical equivalent and cylinder were significantly higher in WFO subgroups(P≤0.003).In moderate myopia group,a higher percentage of eyes with a postoperative cylinder≤0.25 D was found in the WFG subgroup(90.6%vs 65.5%,P=0.002).In low and moderate myopia groups,the difference vector was significantly higher in the WFO subgroup compared to WFG(P〈0.001).In moderate myopia group,the magnitude(P=0.008)and angle of error(P〈0.001)were also significantly higher in the WFO subgroup.Significantlyless induction of high order aberrations were found with WFG treatments in both low and moderate myopia groups(P≤0.006).CONCLUSION:A more efficacious correction of myopic astigmatism providing a better visual outcome is achieved with WFG LASIK compared to WFO LASIK.展开更多
Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission wit...Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission within the respective intermanifold transitions of ^4F3/2→^4I9/2are investigated. The 946.0-nm line shifts toward the shorter wavelength and broadens. In addition, the threshold power and slope efficiency of the 946.0-nm laser line are quantified with temperature.The lower the temperature, the lower the threshold power is and the higher the slope efficiency of the 946.0-nm laser line is,thus the higher the laser output is. This phenomenon is attributed to the ion-phonon interaction and the thermal population in the ground state.展开更多
Multifocal intraocular lenses(IOLs) are currently usually implanted for the treatment of cataracts because they have been proved to be superior to monofocal IOLs with respect to spectacle independence. In turn, they a...Multifocal intraocular lenses(IOLs) are currently usually implanted for the treatment of cataracts because they have been proved to be superior to monofocal IOLs with respect to spectacle independence. In turn, they are associated with a higher prevalence of dysphotopsia symptoms that is one of the most common causes of patient dissatisfaction. Neuroadaptation seems to play a major role in the optimal adaptation to multifocal IOLs. In this context, the development of strategies that facilitate the neuroadaptation process to multifocality might be an effective strategy to reduce patients' dissatisfaction. Video games have been proved to be effective for the improvement of visual acuity and for the promotion of neuroplasticity in elderly subjects and other populations with cortical-related visual impairment. This narrative review highlights the physiological potential of video games as a perceptual strategy to improve visual acuity and promote neuroplasticity in patients using multifocalIOLs, although research is still needed to confirm these benefits in this specific population, with only one comparative study to this date providing evidence of them.展开更多
AIM： To evaluate the prevalence of eye symptoms in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and sixteen VDU users with flat-panel display from an...AIM： To evaluate the prevalence of eye symptoms in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and sixteen VDU users with flat-panel display from an urban population participated in the study; their ages ranging from 20 to 34y. There were 60 females and 56 males. An eye examination to rule out the presence of significant uncorrected refractive errors, general binocular dysfunctions and eye conditions was carried out. In order to determine and quantify the type and nature of eye symptoms, participants were asked to answer written questionnaire and the results were grouped by gender, age and number of hours a day spent using a VDU. RESULTS： Seventy-two percent of participants reported eye symptoms related to VDU use. Eye symptoms from moderate-to-severe were found in 23% of participants. The main symptom was moderate-to- severe tired eyes （14%）; followed by sensitivity to bright lights （12%）, blurred vision at far distances （10%）, eyestrain or dry eye or irritated or burning eyes （9%）, difficulty in refocusing from one distance to another or headache （8%） and blurred vision at near or intermediate distances （〈4%）. Eye symptoms were greater among females （P=0.005） and increased with VDU use, markedly above 6h spent using a VDU in a typical day （P=0.01）. CONCLUSION： Significant eye symptoms relate to VDU use often occur and should not be underestimated. The increasing use of electronic devices with flat-panel display should prompt users to take appropriate measures to prevent or to relieve the eye symptoms arising from their use.展开更多
The optical limiting properties of the mixed liquid of carbon black suspensions （CBS） and green tea solution were studied by using an 8 ns laser pulse at 532 nm. The optical limiting effects of the CBS and mixed liq...The optical limiting properties of the mixed liquid of carbon black suspensions （CBS） and green tea solution were studied by using an 8 ns laser pulse at 532 nm. The optical limiting effects of the CBS and mixed liquid have been compared between 5 and 10 Hz repetition frequencies with nanosecond laser pulse. The experimental results indicate that the optical limiting threshold of the sample with the incidence laser at 10 Hz repetition frequency is lower than at 5 Hz repetition frequency. The possible reasons for the influence of the repetition frequency on the samples are discussed. And by observing the optical radiant distributions when the laser pulse passing through different samples, a possible mechanism for the observed effects is suggested. At the same time, the result shows that the optical limiting of CBS is the dominant factor to optical limiting of the mixed liquid.展开更多
A multiple-image encryption method based on two-step phase-shifting interferometry （PSI） and spatial multiplexing of a smooth compressed signal is proposed. In the encoding and encryption process, with the help of f...A multiple-image encryption method based on two-step phase-shifting interferometry （PSI） and spatial multiplexing of a smooth compressed signal is proposed. In the encoding and encryption process, with the help of four index matrices to store original pixel positions, all the pixels of four secret images are firstly reordered in an ascending order; then, the four reordered images are transformed by five-order Haar wavelet transform and performed sparseness operation. After Arnold transform and pixels sampling operation, one combined image can be grouped with the aid of compressive sensing （CS） and spatial multiplexing techniques. Finally, putting the combined image at the input plane of the PSI encryption scheme, only two interferograms ciphertexts can be obtained. During the decoding and decryption, utilizing all the secret key groups and index matrices keys, all the original secret images can be successfully decrypted by a wave-front retrieval algorithm of two-step PSI, spatial de-multiplexing, inverse Arnold transform, inverse discrete wavelet transform, and pixels reordering operation.展开更多
AIM: To evaluate the interchangeability of keratometric and asphericity measurements provided by three measurement systems based on different optical principles.METHODS: A total of 40 eyes of 40 patients with a mean a...AIM: To evaluate the interchangeability of keratometric and asphericity measurements provided by three measurement systems based on different optical principles.METHODS: A total of 40 eyes of 40 patients with a mean age of 34.1 y were included. In all cases, a corneal curvature analysis was performed with IOL-Master(IOLM), iDesign 2(ID2), and Sirius systems(SIR). Differences between instruments for flattest(K1) and steepest(K2) keratometric readings, as well as for magnitude and axis of corneal astigmatism were analyzed. Likewise, differences in asphericity(Q) between SIR and ID2 were also evaluated. RESULTS: Mean differences between devices for K1 were 0.20±0.21(P<0.001),-0.12±0.36(P=0.046) and-0.32±0.36 D(P<0.001) for the comparisons IOLM-SIR, IOLM-ID2 and SIR-ID2, respectively. The ranges of agreement for these comparisons between instruments were 0.41, 0.70, and 0.70 D. For K2, mean differences were 0.31±0.33(P<0.001),-0.08±0.43(P=0.265) and-0.39±0.38 D(P<0.001), with ranges of agreement of 0.65, 0.84, and 0.74 D. Concerning magnitude of astigmatism, ranges of agreement were in the limit of clinical relevance(0.49 D, P=0.011; 0.55 D, P=0.386; 0.43 D, P=0.05). In contrast, ranges of agreement were clinically relevant for astigmatic axis(26.68o, 33.83o and 18.37o, P≥0.121) and for Q between SIR and ID2(0.16, P<0.001). CONCLUSION: The keratometric corneal power, astigmatic axis and asphericity measurements provideby the three systems evaluated cannot be considered as interchangeable, whereas measurements of corneal astigmatism obtained with SIR and ID2 can be considered as interchangeable for clinical purposes.展开更多
Lead halide perovskites have attracted considerable attention as potential candidates for high-performance nano/microlasers,owing to their outstanding optical properties.However,the further development of perovskite m...Lead halide perovskites have attracted considerable attention as potential candidates for high-performance nano/microlasers,owing to their outstanding optical properties.However,the further development of perovskite microlaser arrays(especially based on polycrystalline thin films)produced by the conventional processing techniques is hindered by the chemical instability and surface roughness of the perovskite structures.Herein,we demonstrate a laser patterning of large-scale,highly crystalline perovskite single-crystal films to fabricate reproducible perovskite single-crystal-based microlaser arrays.Perovskite thin films were directly ablated by femtosecond-laser in multiple low-power cycles at a minimum machining line width of approximately 300 nm to realize high-precision,chemically clean,and repeatable fabrication of microdisk arrays.The surface impurities generated during the process can be washed away to avoid external optical loss due to the robustness of the single-crystal film.Moreover,the high-quality,large-sized perovskite single-crystal films can significantly improve the quality of microcavities,thereby realizing a perovskite microdisk laser with narrow linewidth(0.09 nm)and low threshold(5.1µJ/cm2).Benefiting from the novel laser patterning method and the large-sized perovskite single-crystal films,a high power and high color purity laser display with single-mode microlasers as pixels was successfully fabricated.Thus,this study may offer a potential platform for mass-scale and reproducible fabrication of microlaser arrays,and further facilitate the development of highly integrated applications based on perovskite materials.展开更多
This paper reports that the nonlinear refractive index of a novel organic optical storage film doped azodiphenylamine polymer is measured by using the Z-scan technique. The nonlinear refractive index up to 3.7× 1...This paper reports that the nonlinear refractive index of a novel organic optical storage film doped azodiphenylamine polymer is measured by using the Z-scan technique. The nonlinear refractive index up to 3.7× 10^-6 cm^2/W induced by thermo-optical effect is obtained. It indicates that the sample has excellent optical non- linear properties. The physical mechanism of the great nonlinear optical effect is analysed and the optical conjugate characteristic is also discussed with degenerate four-wave-mixing. The phase conjugate wave diffracted from the formative refractive index grating in the sample is acquired and its equivalent reflectivity reaches about 22%. On this basis, the reflective wave phase-conjugated mirror system was designed, and the image aberration experienced in propagation in the storage experiment is corrected by using the system.展开更多
This paper presents the anisotropic optical feedback of a single frequency intra-cavity He-Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial lin...This paper presents the anisotropic optical feedback of a single frequency intra-cavity He-Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial linear polarized one. Two intensities with a phase difference were detected, both of which were modulated in the form of cosine wave and a fringe shift corresponds to a λ/2 movement of the feedback mirror. The phase difference can be continuously modulated by the wave plate in the external cavity. Frequency stabilization was used to stabilize the laser frequency so as to enlarge the measuring range and improve the measurement precision. This anisotropic optical feedback system offers a potential displacement measurement technology with the function of subdivision of λ/2 and in-time direction judgment. The three-mirror Fabry Perot cavity model is used to present the experimental results. Given the lack of need of lasing adjustment, this full intra-cavity laser can significantly improve the simplicity and stability of the optical feedback system.展开更多
We report the optical response characteristics of A1/Ti bilayer transition edge sensors （TESs）, which are mainly comprised of A1/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measure...We report the optical response characteristics of A1/Ti bilayer transition edge sensors （TESs）, which are mainly comprised of A1/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measurement was performed in a 3He sorption refrigerator and the device＇s response to optical pulses was investigated using a pulsed laser source. Based on these measurements, we obtained the effective recovery time （τeff） of the devices at different biases and discussed the dependence of Veff on the bias. The device with a 940 μm × 940 μm continuous suspended SiN membrane demonstrated a fast response speed with τeff = 3.9 μs, which indicates a high temperature sensitivity （a = T/R·dR/dT = 326）. The results also showed that the TES exhibits good linearity under optical pulses of variable widths.展开更多
文摘AIM:To compare the 12-month outcomes of visual performance and patient satisfaction of a higherorder aspheric monofocal intraocular lens(IOL)and a conventional monofocal IOL.METHODS:Prospective,randomized,comparative,double-blinded study including 22 patients who underwent bilateral cataract surgery with implantation of the Tecnis Eyhance ICB00 IOL in one eye(ICB00 group)and the Tecnis ZCB00 IOL in the fellow eye(ZCB00 group).Uncorrected distance(UDVA),corrected distance(CDVA),uncorrected intermediate(UIVA),distance-corrected intermediate(DCIVA),uncorrected near(UNVA),and distance-corrected near visual acuities(DCNVA)were evaluated during a 12-month follow-up.Contrast sensitivity,defocus curves,and reading text size were also evaluated.Patient satisfaction was assessed with a questionnaire at the 6-month postoperative visit.RESULTS:Mean postoperative logMAR UDVA was 0.01±0.12 and-0.02±0.10 in ICB00 and ZCB00 groups,respectively(P=0.37).Mean logMAR UIVA was 0.32±0.19 and 0.45±0.16 in ICB00 and ZCB00 groups,respectively(P=0.010).Differences between groups in UNVA did not reach statistical significance(P=0.16).The intermediate reading acuity at 66 cm(P=0.02)and 80 cm(P=0.04)was significantly better in the ICB00 group.Postoperative contrast sensitivity results did not differ significantly between groups(P>0.05).Patients reported high overall satisfaction,with 62%of patients using spectacles for reading in everyday life.CONCLUSION:The eyes of patients implanted with the enhanced monofocal IOL evaluated have significantly better visual acuity for intermediate distances with the same contrast sensitivity as a conventional monofocal IOL.
文摘AIM:To assess whether the implantation of a posterior chamber phakic intraocular lens produces changes in optical coherence tomography(OCT)measurements of macular thickness(MT)and two parameters that define the structure of the optic nerve,the peripapillary nerve fiber layer(RNFL)and the Bruch’s membrane opening-minimum rim width(BMO-MRW).METHODS:This nonrandomized prospective pre-post study included 86 eyes of 48 patients(age,20-47y;axial length:23.10-28.95 mm)scheduled for myopia or myopic astigmatism correction with implantation of the implantable collamer lens(ICL).Eyes with glaucoma or any other ocular disease that could alter OCT results were excluded.RNFL,BMO-MRW and MT were measured preoperatively,and at 1 and 6mo after surgery using spectral-domain OCT.Changes between preoperative and postoperative values were evaluated.RESULTS:There was a significant increase in BMOMRW at 1mo(mean change:3.48±15.07μm,P=0.041).No significant changes were found during the rest of followup(1-6mo postop.,P=0.623).There was also a significant increase in RNFL thickness at 1mo af ter surger y(1.45±2.18μm,P<0.001),but with a significant reduction from 1 to 6mo postoperatively(P=0.002).Regarding MT,it increased significantly at 1mo(2.46±3.76μm,P<0.001),with a significant decrease afterwards(P=0.048).Measurements of the three parameters at 6mo were slightly superior to preoperative values(P<0.01).CONCLUSION:Minimal changes are induced in BMOMRW,RNFL and MT after ICL implantation in healthy eyes,confirming the safety of the surgical procedure regarding the structure of the optic nerve head and the macula,and indicating that this phakic intraocular lens seems to have a slight impact on OCT measurements.
文摘AIM:To investigate the prevalence of visual impairment(VI)and provide an estimation of uncorrected refractive errors in school-aged children,conducted by optometry students as a community service.METHODS:The study was cross-sectional.Totally 3343 participants were included in the study.The initial examination involved assessing the uncorrected distance visual acuity(UDVA)and visual acuity(VA)while using a+2.00 D lens.The inclusion criteria for a subsequent comprehensive cycloplegic eye examination,performed by an optometrist,were as follows:a UDVA<0.6 decimal(0.20 logMAR)and/or a VA with+2.00 D≥0.8 decimal(0.96 logMAR).RESULTS:The sample had a mean age of 10.92±2.13y(range 4 to 17y),and 51.3%of the children were female(n=1715).The majority of the children(89.7%)fell within the age range of 8 to 14y.Among the ethnic groups,the highest representation was from the Luhya group(60.6%)followed by Luo(20.4%).Mean logMAR UDVA choosing the best eye for each student was 0.29±0.17(range 1.70 to 0.22).Out of the total,246 participants(7.4%)had a full eye examination.The estimated prevalence of myopia(defined as spherical equivalent≤-0.5 D)was found to be 1.45%of the total sample.While around 0.18%of the total sample had hyperopia value exceeding+1.75 D.Refractive astigmatism(cil<-0.75 D)was found in 0.21%(7/3343)of the children.The VI prevalence was 1.26%of the total sample.Among our cases of VI,76.2%could be attributed to uncorrected refractive error.Amblyopia was detected in 0.66%(22/3343)of the screened children.There was no statistically significant correlation observed between age or gender and refractive values.CONCLUSION:The primary cause of VI is determined to be uncorrected refractive errors,with myopia being the most prevalent refractive error observed.These findings underscore the significance of early identification and correction of refractive errors in school-aged children as a means to alleviate the impact of VI.
文摘AIM:To evaluate the reliability of measurements of corneal changes with accommodation in healthy eyes using a Scheimpflug imaging-based system and how these measurements distribute in the normal population.METHODS:Prospective,non-randomized,comparative study including 27 healthy subjects(54 eyes),including emmetropia(13 eyes),myopia(17 eyes),hyperopia(4 eyes)and astigmatism(20 eyes)groups.In all cases,a complete eye examination was performed,including the analysis of corneal changes with different accommodative stimuli(+2.00,0.00 and-3.00 D)using the Pentacam AXL system.The investigation was structured in 2 phases:repeatability analysis and characterization of accommodation-related corneal changes in healthy populations.RESULTS:In the repeatability analysis,the index of height asymmetry(IHA)showed the greatest variability with the three accommodative stimuli,being the results for the rest of parameters acceptable.The group of emmetropes showed significant differences with accommodative changes in the position of maximum keratometry(Kmax;P<0.05),whereas in the astigmatism group,significant changes were not only observed in the position of Kmax,but also in minimum corneal thickness(MCT),corneal spherical aberration,and total and low order aberration root mean square(all P<0.05).Likewise,a significant difference was found in the displacement of the X position of Kmax with+2.00 D and-3.00 D in the myopia group(P=0.033)as well as in changes with+2.00 D and-3.00 D in the magnitude of the position vector of Kmax in the emmetropia group(P<0.05).No significant changes were found between accommodative stimuli in the displacement of coordinates of MCT(P≥0.109).CONCLUSION:The position of Kmax and MCT in healthy corneas can change significantly when presenting different accommodative stimuli using the accommodation mode of the Pentacam system,with different trends in these accommodation-related corneal changes between refractive errors.Likewise,the consistency of the measurements obtained with Scheimpflug has been confirmed.
基金supported by the National Natural Science Foundation of China(Nos.41905028,91544218,12134013,and 62127818)the National Key Researchand Development Program of China(No.2017YFC0209504)+3 种基金Anhui Provincial Natural Science Foundation(Nos.1908085MD114 and 2108085MD139)the Hefei Municipal Natural Science Foundation(No.2021007)the Key Research&Development program of Anhui Province(No.202104a05020010)the HFIPS Director’s Fund(Nos.YZJJ2022QN04 and BJPY2021A04)。
文摘Under high relative humidity(RH)conditions,the release of volatile components(such as acetate)has a significant impact on the aerosol hygroscopicity.In this work,one surface plasmon resonance microscopy(SPRM)measurement system was introduced to determine the hygroscopic growth factors(GFs)of three acetate aerosols separately or mixed with glucose at different RHs.For Ca(CH_(3)COO)_(2) or Mg(CH_(3)COO)_(2) aerosols,the hygroscopic growth trend of each time was lower than that of the previous time in three cyclic humidification from 70% RH to 90% RH,which may be due to the volatility of acetic acid leading to the formation of insoluble hydroxide(Ca(OH)_(2) or Mg(OH)_(2))under high RH conditions.Then the third calculated GF(using the Zdanovskii-Stokes-Robinson method)for Ca(CH_(3)COO)_(2) or Mg(CH_(3)COO)_(2) in bicomponent aerosols with 1:1 mass ratio were 3.20% or 5.33% lower than that of the first calculated GF at 90% RH.The calculated results also showed that the hygroscopicity change of bicomponent aerosol was negatively correlated with glucose content,especially when the mass ratio of Mg(CH_(3)COO)_(2) to glucose was 1:2,the GF at 90% RH only decreased by4.67% after three cyclic humidification.Inductively coupled plasma atomic emission spectrum(ICP-AES)based measurements also indicated that the changes of Mg^(2+)concentration in bicomponent was lower than that of the single-component.The results of this study reveal thatduring the efflorescence transitions of atmospheric nanoparticles,the organic acids diffusion rate may be inhibited by the coating effect of neutral organic components,and the particles aging cycle will be prolonged.
文摘The Chinese-Russian Workshop on Biophotonics and Biomedical Optics 2023 was held online twice on 18–21 September and 25–26 September 2023.The bilateral workshop brought together both Russian and Chinese scientists,engineers,and clinical researchers from a variety of disciplines engaged in applying optical science,photonics,and imaging technologies to problems in biology and medicine.During the workshops,two plenary lectures and twenty invited presentations were presented.This special issue selects some papers from both Russian and Chinese sides,consisting of one review and seven original research articles.
基金the National Key Research and Development Program of China(2022YFB3607300)the National Natural Science Foundation of China(62322512 and 12134013)+3 种基金the Chinese Acad-emy of Sciences Project for Young Scientists in Basic Research(YSBR-049)support from the University of Science and Technology of China’s Center for Micro and Nanoscale Research and Fabricationsupported by the China Postdoctoral Science Foundation(2023M743364)supercomputing system in Hefei Advanced Computing Center and the Supercomputing Center of University of Science and Technology of China.
文摘Optical data storage(ODS)is a low-cost and high-durability counterpart of traditional electronic or mag-netic storage.As a means of enhancing ODS capacity,the multiple recording layer(MRL)method is more promising than other approaches such as reducing the recording volume and multiplexing technology.However,the architecture of current MRLs is identical to that of recording data into physical layers with rigid space,which leads to either severe interlayer crosstalk or finite recording layers constrained by the short working distances of the objectives.Here,we propose the concept of hybrid-layer ODS,which can record optical information into a physical layer and multiple virtual layers by using high-orthogonality random meta-channels.In the virtual layer,32 images are experimentally reconstructed through holog-raphy,where their holographic phases are encoded into 16 printed images and complementary images in the physical layer,yielding a capacity of 2.5 Tbit cm^(-3).A higher capacity is achievable with more virtual layers,suggesting hybrid-layer ODS as a possible candidate for next-generation ODS.
文摘AIM： To determine the presence of symptomatic accommodative and non-strabismic binocular dysfunctions （A.sBD） in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and one VDU users, aged between 20 to 34y, initially participated in the study. This study excluded contact-lens wearers and subjects who had undergone refractive surgery or had any systemic or ocular disease. First, subjects were asked about the type and nature of eye symptoms they experienced during VDU use. Then, a thorough eye examination excluded those subjects with a significant uncorrected refractive error or other problem, such as ocular motility disorders, vertical deviation, strabismus and eye diseases. Finally, the remaining participants underwent an exhaustive assessment of their accommodative and binocular vision status. RESULTS： Eighty-nine VDU users （46 females and 43 males） were included in this study. They used flat-panel displays for an average of 5±1.9h a day. Twenty subjects presented A.sBD （22.5%）. Convergence excess was the most frequent non-strabismic binocular dysfunction （9 subjects）, followed by fusional vergence dysfunction （3 subjects） and convergence insufficiency （2 subjects）. Within the accommodative dysfunctions, accommodative excess was the most common （4 subjects）, followed by accommodative insufficiency （2 subjects）. Moderate to severe eye symptoms were found in 13 subjects with ANSBD. CONCLUSION： Significant eye symptoms in VDU users with accommodative and/or non-strabismic binocular dysfunctions often occur and should not be underestimated; therefore, an appropriate evaluation of accommodative and binocular vision status is more important for this population,
基金Spanish Ministry of Education and Science(No.DPI2008-06455-C02-01)European Union and the Spanish Agency for International Cooperation(AECI)(No.D/030286/10)
文摘AIM:To evaluate the accuracy of spherical equivalent(SE) estimates of a double-pass system and to compare it with retinoscopy,subjective refraction and a table mounted autorefractor.METHODS:Non-cycloplegic refraction was performed on 125 eyes of 65 healthy adults(age 23.5±3.0 years) from October 2010 to January 2011 using retinoscopy,subjective refraction,autorefraction(Auto kerato refractometer TOPCON KR-8100,Japan) and a double pass system(Optical Quality Analysis System,OQAS,Visiometrics S.L.,Spain).Nine consecutive measurements with the double-pass system were performed on a subgroup of 22 eyes to assess repeatability.To evaluate the trueness of the OQAS instrument,the SE laboratory bias between the double pass system and the other techniques was calculated.RESULTS:The SE mean coefficient of repeatability obtained was 0.22D.Significant correlations could be established between the OQAS and the SE obtained with retinoscopy(r=0.956,P【0.001),subjective refraction(r=0.955,P【0.001) and autorefraction(r=0.957,P【0.001).The differences in SE between the double-pass system and the other techniques were significant(P【0.001),but lacked clinical relevance except for retinoscopy;Retinoscopy gave more hyperopic values than the double-pass system-0.51±0.50D as well as the subjective refraction-0.23±0.50D;More myopic values were achieved by means of autorefraction 0.24±0.49D. CONCLUSION:The double-pass system provides accurate and reliable estimates of the SE that can be used for clinical studies.This technique can determine the correct focus position to assess the ocular optical quality.However,it has a relatively small measuring range in comparison with autorefractors(-8.00 to +5.00D),and requires prior information on the refractive state of the patient.
基金Partially supported by a grant from Abbott Medical Optics
文摘AIM:To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis(LASIK)in eyes with myopic astigmatism using wavefront-guided(WFG)and wavefront-optimized(WFO)ablation profiles.METHODS:Prospective study included 221 eyes undergoing LASIK:99 and 122 eyes with low and moderate myopic astigmatism(low and moderate myopia groups).Two subgroups were differentiated in each group according to the ablation profile:WFG subgroup,109 eyes(45/64,low/moderate myopia groups)treated using the Advanced Custom Vue platform(Abbott Medical Optics Inc.),and WFO subgroup,112 eyes(54/58,low/moderate myopia groups)treated using the EX-500 platform(Alcon).Clinical outcomes were evaluated during a 6-month follow-up,including a vector analysis of astigmatic changes.RESULTS:Significantly better postoperative uncorrected visual acuity and efficacy index was found in the WFG subgroups of each group(P≤0.041).Postoperative spherical equivalent and cylinder were significantly higher in WFO subgroups(P≤0.003).In moderate myopia group,a higher percentage of eyes with a postoperative cylinder≤0.25 D was found in the WFG subgroup(90.6%vs 65.5%,P=0.002).In low and moderate myopia groups,the difference vector was significantly higher in the WFO subgroup compared to WFG(P〈0.001).In moderate myopia group,the magnitude(P=0.008)and angle of error(P〈0.001)were also significantly higher in the WFO subgroup.Significantlyless induction of high order aberrations were found with WFG treatments in both low and moderate myopia groups(P≤0.006).CONCLUSION:A more efficacious correction of myopic astigmatism providing a better visual outcome is achieved with WFG LASIK compared to WFO LASIK.
基金Project supported by Estahban Branch,Islamic Azad University
文摘Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission within the respective intermanifold transitions of ^4F3/2→^4I9/2are investigated. The 946.0-nm line shifts toward the shorter wavelength and broadens. In addition, the threshold power and slope efficiency of the 946.0-nm laser line are quantified with temperature.The lower the temperature, the lower the threshold power is and the higher the slope efficiency of the 946.0-nm laser line is,thus the higher the laser output is. This phenomenon is attributed to the ion-phonon interaction and the thermal population in the ground state.
基金Coco-Martin MB,Maldonado-López MJ,Molina-Martín A and Pi?ero DP are supported by CDTI(Centro para el Desarrollo Tecnológico Industrial,Ministry of Economy and Competitiveness of Spain)by means of the program PID(“Proyectos de Investigación y Desarrollo”)The author Pi?ero DP has been also supported by the Ministry of Economy,Industry and Competitiveness of Spain within the program Ramón y Cajal(RYC-2016-20471)Valenzuela PL is supported by a contract granted by University of Alcalá(FPI2016)
文摘Multifocal intraocular lenses(IOLs) are currently usually implanted for the treatment of cataracts because they have been proved to be superior to monofocal IOLs with respect to spectacle independence. In turn, they are associated with a higher prevalence of dysphotopsia symptoms that is one of the most common causes of patient dissatisfaction. Neuroadaptation seems to play a major role in the optimal adaptation to multifocal IOLs. In this context, the development of strategies that facilitate the neuroadaptation process to multifocality might be an effective strategy to reduce patients' dissatisfaction. Video games have been proved to be effective for the improvement of visual acuity and for the promotion of neuroplasticity in elderly subjects and other populations with cortical-related visual impairment. This narrative review highlights the physiological potential of video games as a perceptual strategy to improve visual acuity and promote neuroplasticity in patients using multifocalIOLs, although research is still needed to confirm these benefits in this specific population, with only one comparative study to this date providing evidence of them.
文摘AIM： To evaluate the prevalence of eye symptoms in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and sixteen VDU users with flat-panel display from an urban population participated in the study; their ages ranging from 20 to 34y. There were 60 females and 56 males. An eye examination to rule out the presence of significant uncorrected refractive errors, general binocular dysfunctions and eye conditions was carried out. In order to determine and quantify the type and nature of eye symptoms, participants were asked to answer written questionnaire and the results were grouped by gender, age and number of hours a day spent using a VDU. RESULTS： Seventy-two percent of participants reported eye symptoms related to VDU use. Eye symptoms from moderate-to-severe were found in 23% of participants. The main symptom was moderate-to- severe tired eyes （14%）; followed by sensitivity to bright lights （12%）, blurred vision at far distances （10%）, eyestrain or dry eye or irritated or burning eyes （9%）, difficulty in refocusing from one distance to another or headache （8%） and blurred vision at near or intermediate distances （〈4%）. Eye symptoms were greater among females （P=0.005） and increased with VDU use, markedly above 6h spent using a VDU in a typical day （P=0.01）. CONCLUSION： Significant eye symptoms relate to VDU use often occur and should not be underestimated. The increasing use of electronic devices with flat-panel display should prompt users to take appropriate measures to prevent or to relieve the eye symptoms arising from their use.
基金supported by the National Science Foundation for Post-doctoral Scientists of China (Grant No 20060400418)the Key Scientific Research Foundation of the Ordnance Engineering College,China (Grant No YJJXM05002)
文摘The optical limiting properties of the mixed liquid of carbon black suspensions （CBS） and green tea solution were studied by using an 8 ns laser pulse at 532 nm. The optical limiting effects of the CBS and mixed liquid have been compared between 5 and 10 Hz repetition frequencies with nanosecond laser pulse. The experimental results indicate that the optical limiting threshold of the sample with the incidence laser at 10 Hz repetition frequency is lower than at 5 Hz repetition frequency. The possible reasons for the influence of the repetition frequency on the samples are discussed. And by observing the optical radiant distributions when the laser pulse passing through different samples, a possible mechanism for the observed effects is suggested. At the same time, the result shows that the optical limiting of CBS is the dominant factor to optical limiting of the mixed liquid.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61775121,61307003,61405122,and 11574311)Key R&D Program of Shandong Province,China(Grant No.2018GGX101002)+1 种基金the Natural Science Foundation of Shandong Province,China(Grant No.R2016FM03)the Fundamental Research Funds of Shandong University,China(Grant No.2015GN031)
文摘A multiple-image encryption method based on two-step phase-shifting interferometry （PSI） and spatial multiplexing of a smooth compressed signal is proposed. In the encoding and encryption process, with the help of four index matrices to store original pixel positions, all the pixels of four secret images are firstly reordered in an ascending order; then, the four reordered images are transformed by five-order Haar wavelet transform and performed sparseness operation. After Arnold transform and pixels sampling operation, one combined image can be grouped with the aid of compressive sensing （CS） and spatial multiplexing techniques. Finally, putting the combined image at the input plane of the PSI encryption scheme, only two interferograms ciphertexts can be obtained. During the decoding and decryption, utilizing all the secret key groups and index matrices keys, all the original secret images can be successfully decrypted by a wave-front retrieval algorithm of two-step PSI, spatial de-multiplexing, inverse Arnold transform, inverse discrete wavelet transform, and pixels reordering operation.
基金supported by the Ministry of Economy,Industry and Competitiveness of Spain within the program Ramón y Cajal,RYC-2016-20471Additionally he received an unrestricted grant from Johnson and Johnson Vision for the performance of this research
文摘AIM: To evaluate the interchangeability of keratometric and asphericity measurements provided by three measurement systems based on different optical principles.METHODS: A total of 40 eyes of 40 patients with a mean age of 34.1 y were included. In all cases, a corneal curvature analysis was performed with IOL-Master(IOLM), iDesign 2(ID2), and Sirius systems(SIR). Differences between instruments for flattest(K1) and steepest(K2) keratometric readings, as well as for magnitude and axis of corneal astigmatism were analyzed. Likewise, differences in asphericity(Q) between SIR and ID2 were also evaluated. RESULTS: Mean differences between devices for K1 were 0.20±0.21(P<0.001),-0.12±0.36(P=0.046) and-0.32±0.36 D(P<0.001) for the comparisons IOLM-SIR, IOLM-ID2 and SIR-ID2, respectively. The ranges of agreement for these comparisons between instruments were 0.41, 0.70, and 0.70 D. For K2, mean differences were 0.31±0.33(P<0.001),-0.08±0.43(P=0.265) and-0.39±0.38 D(P<0.001), with ranges of agreement of 0.65, 0.84, and 0.74 D. Concerning magnitude of astigmatism, ranges of agreement were in the limit of clinical relevance(0.49 D, P=0.011; 0.55 D, P=0.386; 0.43 D, P=0.05). In contrast, ranges of agreement were clinically relevant for astigmatic axis(26.68o, 33.83o and 18.37o, P≥0.121) and for Q between SIR and ID2(0.16, P<0.001). CONCLUSION: The keratometric corneal power, astigmatic axis and asphericity measurements provideby the three systems evaluated cannot be considered as interchangeable, whereas measurements of corneal astigmatism obtained with SIR and ID2 can be considered as interchangeable for clinical purposes.
基金the support from the National Natural Science Foundation of China (No. 61925506)the Natural Science Foundation of Shanghai (No. 20JC1414605)+1 种基金Hangzhou Science and Technology Bureau of Zhejiang Province (No. TD2020002)the Academic/Technology Research Leader Program of Shanghai (23XD1404500)
文摘Lead halide perovskites have attracted considerable attention as potential candidates for high-performance nano/microlasers,owing to their outstanding optical properties.However,the further development of perovskite microlaser arrays(especially based on polycrystalline thin films)produced by the conventional processing techniques is hindered by the chemical instability and surface roughness of the perovskite structures.Herein,we demonstrate a laser patterning of large-scale,highly crystalline perovskite single-crystal films to fabricate reproducible perovskite single-crystal-based microlaser arrays.Perovskite thin films were directly ablated by femtosecond-laser in multiple low-power cycles at a minimum machining line width of approximately 300 nm to realize high-precision,chemically clean,and repeatable fabrication of microdisk arrays.The surface impurities generated during the process can be washed away to avoid external optical loss due to the robustness of the single-crystal film.Moreover,the high-quality,large-sized perovskite single-crystal films can significantly improve the quality of microcavities,thereby realizing a perovskite microdisk laser with narrow linewidth(0.09 nm)and low threshold(5.1µJ/cm2).Benefiting from the novel laser patterning method and the large-sized perovskite single-crystal films,a high power and high color purity laser display with single-mode microlasers as pixels was successfully fabricated.Thus,this study may offer a potential platform for mass-scale and reproducible fabrication of microlaser arrays,and further facilitate the development of highly integrated applications based on perovskite materials.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 19834030 and 50533010）.
文摘This paper reports that the nonlinear refractive index of a novel organic optical storage film doped azodiphenylamine polymer is measured by using the Z-scan technique. The nonlinear refractive index up to 3.7× 10^-6 cm^2/W induced by thermo-optical effect is obtained. It indicates that the sample has excellent optical non- linear properties. The physical mechanism of the great nonlinear optical effect is analysed and the optical conjugate characteristic is also discussed with degenerate four-wave-mixing. The phase conjugate wave diffracted from the formative refractive index grating in the sample is acquired and its equivalent reflectivity reaches about 22%. On this basis, the reflective wave phase-conjugated mirror system was designed, and the image aberration experienced in propagation in the storage experiment is corrected by using the system.
基金supported by the National Natural Science Foundation of China (Grant No 60437010)
文摘This paper presents the anisotropic optical feedback of a single frequency intra-cavity He-Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial linear polarized one. Two intensities with a phase difference were detected, both of which were modulated in the form of cosine wave and a fringe shift corresponds to a λ/2 movement of the feedback mirror. The phase difference can be continuously modulated by the wave plate in the external cavity. Frequency stabilization was used to stabilize the laser frequency so as to enlarge the measuring range and improve the measurement precision. This anisotropic optical feedback system offers a potential displacement measurement technology with the function of subdivision of λ/2 and in-time direction judgment. The three-mirror Fabry Perot cavity model is used to present the experimental results. Given the lack of need of lasing adjustment, this full intra-cavity laser can significantly improve the simplicity and stability of the optical feedback system.
基金supported by the National Basic Research Program of China(Grant No.2011CBA00304)Tsinghua University Initiative Scientific Research Program,China(Grant No.20131089314)the National Natural Science Foundation of China(Grant Nos.60836001 and 11273023)
文摘We report the optical response characteristics of A1/Ti bilayer transition edge sensors （TESs）, which are mainly comprised of A1/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measurement was performed in a 3He sorption refrigerator and the device＇s response to optical pulses was investigated using a pulsed laser source. Based on these measurements, we obtained the effective recovery time （τeff） of the devices at different biases and discussed the dependence of Veff on the bias. The device with a 940 μm × 940 μm continuous suspended SiN membrane demonstrated a fast response speed with τeff = 3.9 μs, which indicates a high temperature sensitivity （a = T/R·dR/dT = 326）. The results also showed that the TES exhibits good linearity under optical pulses of variable widths.
