An approximate analytic model is presented to describe spatial structure of refracted electromagnetic field arising at oblique incidence of a Gaussian beam on a plane boundary of an absorbing homogeneous medium. The a...An approximate analytic model is presented to describe spatial structure of refracted electromagnetic field arising at oblique incidence of a Gaussian beam on a plane boundary of an absorbing homogeneous medium. The analytic solution is obtained by asymptotic approximation of a Fourier field integral under the condition of great beam width in comparison with a wavelength (the geometrical-optics approximation). This model can be used also for approximate simulation of refracted field in the cases of beam incidence near the critical angle on transparent or absorbing (amplifying) refracting medium, if one artificially introduces the additional absorption (amplification), whose value is proportional to the ratio of the wavelength and the effective beam width. It is shown that the analytic model reflects the general features of refracted field at total internal reflection.展开更多
Three-component seismic exploration through P-wave source and three-component geophone is an effective technique used in complicated reservoir exploration.In three-component seismic exploration data processing,one of ...Three-component seismic exploration through P-wave source and three-component geophone is an effective technique used in complicated reservoir exploration.In three-component seismic exploration data processing,one of the difficulties is static correction of converted wave.This paper analyzes propagation characteristics of non-converted and converted refracted waves,and discovers a favor-able condition for the formation of converted refracted wave,i.e.the velocity of overlaying medium S wave is much lower than that of underlying medium S wave.In addition,the paper proposes the static correction method of converted wave based on PPS converted refracted wave,and processes the real three-component seismic data with better results of static correction of converted wave.展开更多
AIM:To evaluate the efficacy of the total computer vision syndrome questionnaire(CVS-Q)score as a predictive tool for identifying individuals with symptomatic binocular vision anomalies and refractive errors.METHODS:A...AIM:To evaluate the efficacy of the total computer vision syndrome questionnaire(CVS-Q)score as a predictive tool for identifying individuals with symptomatic binocular vision anomalies and refractive errors.METHODS:A total of 141 healthy computer users underwent comprehensive clinical visual function assessments,including evaluations of refractive errors,accommodation(amplitude of accommodation,positive relative accommodation,negative relative accommodation,accommodative accuracy,and accommodative facility),and vergence(phoria,positive and negative fusional vergence,near point of convergence,and vergence facility).Total CVS-Q scores were recorded to explore potential associations between symptom scores and the aforementioned clinical visual function parameters.RESULTS:The cohort included 54 males(38.3%)with a mean age of 23.9±0.58y and 87 age-matched females(61.7%)with a mean age of 23.9±0.53y.The multiple regression model was statistically significant[R²=0.60,F=13.28,degrees of freedom(DF=17122,P<0.001].This indicates that 60%of the variance in total CVS-Q scores(reflecting reported symptoms)could be explained by four clinical measurements:amplitude of accommodation,positive relative accommodation,exophoria at distance and near,and positive fusional vergence at near.CONCLUSION:The total CVS-Q score is a valid and reliable tool for predicting the presence of various nonstrabismic binocular vision anomalies and refractive errors in symptomatic computer users.展开更多
AIM:To ascertain the pattern of ocular morbidity in a population of primary school children in rural Kenya as it is a prerequisite for planning effective preventive and therapeutic strategies.METHODS:A cross-sectional...AIM:To ascertain the pattern of ocular morbidity in a population of primary school children in rural Kenya as it is a prerequisite for planning effective preventive and therapeutic strategies.METHODS:A cross-sectional survey of ocular symptoms and clinical eye examinations were performed in a sample of 35 rural primary schools in the semi-arid region of Kajiado West sub-county in S.W.Kenya,amongst a seminomadic tribe(Maasai).Students in Grades 1-8 were included.Visual acuity was measured using the Snellen“tumbling E”chart at 6 m.Children with symptoms of refractive error underwent non-cycloplegic refraction.RESULTS:A total of 2036 children(1084 males)between the ages of 4-20y were examined.Conjunctival actinic changes were present in 22%(442/2036).Nine cases were seen with a potential squamous carcinoma.No overt classical ocular signs of vitamin A deficiency were noted,although 181(8.9%)children complained of nyctalopia.Three hundred thirty-six(16.5%)children had a visual acuity worse than 6/12 in either eye,were unable to read N10 near text at 40 cm or had symptoms suggestive of refractive error.Refractive data led to an estimate of hyperopia of+1.00 D or more in 3.9%and of myopia of-0.50 D or more in either eye in 3.0%of the study population.CONCLUSION:Solar exposure-and dust-related conjunctival pathology is common.As this may develop into potentially sight-or even life-threatening conditions,it warrants further study,and preventive strategies may be needed.Complaints of nyctalopia were common and could suggest vitamin A deficiency.The prevalence of refractive errors is low in this rural African population.展开更多
AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 group...AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs.展开更多
Dear Editor,We present this case report which discusses a patient who underwent flap amputation after repeated attempts to resolve persistent and severe epithelial ingrowth following laser-assisted in situ keratomileu...Dear Editor,We present this case report which discusses a patient who underwent flap amputation after repeated attempts to resolve persistent and severe epithelial ingrowth following laser-assisted in situ keratomileusis(LASIK)surgery.Epithelial ingrowth is a known complication of LASIK surgery,typically manageable with minimal measures.However,severe cases may necessitate more aggressive interventions,such as flap amputation[1].LASIK is a widely performed refractive surgery with high success rates and excellent visual outcome[2].展开更多
Ocular biological characteristics and refractive errors in children with unilateral congenital ptosis Yu-Ying Sun,Bing-Ying Lin,Zhen Mao,Xuan-Wei Liang,Cui-Yu Zhang,Dan-Ping Huang,Yao Ni,Zuo-Hong Li Int J Ophthalmol 2...Ocular biological characteristics and refractive errors in children with unilateral congenital ptosis Yu-Ying Sun,Bing-Ying Lin,Zhen Mao,Xuan-Wei Liang,Cui-Yu Zhang,Dan-Ping Huang,Yao Ni,Zuo-Hong Li Int J Ophthalmol 2025;18(4):691-698.DOI:10.18240/ijo.2025.04.16 The author requests to change the authorship and affiliations as follows.展开更多
Gradient refractive index(GRIN)metalenses are increasingly valued in high-frequency communication due to their exceptional radiation performance.Ceramics with high dielectric constants and low dielectric losses are id...Gradient refractive index(GRIN)metalenses are increasingly valued in high-frequency communication due to their exceptional radiation performance.Ceramics with high dielectric constants and low dielectric losses are ideal candidates for GRIN metalenses.Digital light processing(DLP)3D printing provides a feasible and efficient approach for manufacturing ceramic GRIN metalenses.However,the scattering of ultraviolet(UV)light by ceramic particles in the slurry reduces the printing accuracy of DLP technology,making it difficult to achieve the intricate structural features required for GRIN metalenses in high-frequency communication.In this work,we propose an approach to improve printing accuracy by optimizing the ceramic slurry composition and implementing a dimensional compensation design strategy.Utilizing geometric optics and the S-parameter inversion method,we design a GRIN metalens consisting of two distinct types of subwavelength unit cells(Y-shaped and circular hole geometries)with a minimum feature size of 160μm.Through a refined slurry formulation and precise design parameter compensation,high-fidelity ceramic GRIN metalenses are successfully fabricated.The fabricated metalens exhibits a maximum gain enhancement of 18.4 dBi and a deflection angle of±30°over a bandwidth of 37.84% in the W-band(75-110 GHz).The highly directional far-field beam radiation and efficient beam steering capabilities highlight the potential of ceramic GRIN metalenses for applications in satellite communications,radar systems,and other high-frequency technologies.展开更多
Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)...Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)sensors.Among them,the traditional surface plasmon polariton(SPP)based on noble metals limits its application beyond the near-infrared(IR)regime due to the large negative permittivity and optical losses.In this contribution,we theoretically proposed a highly sensitive PSHE sensor with the structure of Ge prism-SiC-Si:InAs-sensing medium,by taking advantage of the hybrid surface plasmon phonon polariton(SPPhP)in mid-IR regime.Here,heavily Si-doped InAs(Si:InAs)and SiC excite the SPP and surface phonon polariton(SPhP),and the hybrid SPPhP is realized in this system.More importantly,the designed PSHE sensor based on this SPPhP mechanism achieves the multi-stage RI measurements from 1.00025-1.00225 to 1.70025-1.70225,and the maximal intensity sensitivity and angle sensitivity can be up to 9.4×10^(4)μm/RIU and245°/RIU,respectively.These findings provide a new pathway for the enhancement of PSHE in mid-IR regime,and offer new opportunities to develop highly sensitive RI sensors in multi-scenario applications,such as harmful gas monitoring and biosensing.展开更多
Fiber-optic sensing technology has the advantages of passivity, anti-electromagnetic interference, longdistancemeasurement, high sensitivity and high accuracy, small size, and adaptability to harsh environments such a...Fiber-optic sensing technology has the advantages of passivity, anti-electromagnetic interference, longdistancemeasurement, high sensitivity and high accuracy, small size, and adaptability to harsh environments such ashigh-vacuum, high-pressure, and strong magnetic fields compared with the traditional electrical sensing technology.However, with the increasing application requirements, how to further improve the sensitivity of fiber-optic sensors,extend the detection limit and improve the maintenance-free capability has become one of the core issues of thecurrent research. This paper reviews the principle, preparation, and application of fiber-optic microstructured sensingbased on abrupt field type. It specifically outlines the development and applications of micro-nano optical fibers,photonic crystal optical fibers, optical fiber gratings and structured optical fibers, and lists the main preparationmethods of two types of micro-nano optical fibers from the basic theory of optical fiber microstructured sensordevices.展开更多
AIM:To evaluate the visual function and optical quality in adults aged 80y and older following the bilateral implantation of zonal refractive multifocal intraocular lens(IOL,LS-313 MF30).METHODS:A single-center,non-ra...AIM:To evaluate the visual function and optical quality in adults aged 80y and older following the bilateral implantation of zonal refractive multifocal intraocular lens(IOL,LS-313 MF30).METHODS:A single-center,non-randomized,prospective clinical trial was conducted,involving cataract patients aged 80 y and older.Patients received bilateral implantation of the LS-313 MF30 or CT Asphina 409MP,based on personal preference.Postoperative assessments included uncorrected and corrected visual acuity at distance,intermediate,and near ranges,as well as defocus curve.Subjective evaluations were performed using the visual function(VF-14)questionnaire,spectacle independence rates,and patient satisfaction surveys.Photic phenomena such as glare,halos,and starbursts were also analyzed.RESULTS:The MF30 group(16 eyes from 8 participants,85.38±2.56 y)exhibited superior uncorrected and corrected intermediate and near visual acuity compared to the 409MP group(26 eyes from 13 participants,85.77±2.20 y),while distance visual acuity was comparable between groups.The defocus curve of the MF30 group revealed two peaks at 0.00 D and-3.00 D,indicating a broader depth of focus.Patients in the MF30 group reported higher rates of spectacle independence and greater satisfaction.While photic phenomena such as glare(28.6%vs 18.5%,P=0.584),starburst(9.5%vs 3.7%,P=0.567)and halos(23.8%vs 11.11%,P=0.438)were more prevalent in the MF30 group,they were generally mild and did not significantly impact daily activities.CONCLUSION:Zonal refractive multifocal IOLs provide elderly patients with improved distance and near vision,greater spectacle independence,and greater satisfaction.Although photic phenomena were slightly more frequent with MF30,they are generally reported as non-disruptive and do not affect their daily life compared to monofocal IOLs.展开更多
AIM:To evaluate the effects of refractive errors and binocular vision anomalies on the quality of life(QOL)of university students.METHODS:This cross-sectional analytical study was conducted on university students usin...AIM:To evaluate the effects of refractive errors and binocular vision anomalies on the quality of life(QOL)of university students.METHODS:This cross-sectional analytical study was conducted on university students using simple random sampling.Objective refraction,ocular alignment,vergence and accommodative performance were measured and assessed in all participants.Data on QOL were collected using the College of Optometrists in Vision Development-Quality of Life(COVD-QOL)Questionnaire.The effect of mentioned parameters on the QOL were evaluated.RESULTS:Totally 726 students with mean age of 21.35±1.88y were evaluated in this study,51.5%of whom were female.Esophoria was caused significantly lower QOL in the domains of somatic symptoms and occupationalphysical symptoms(P<0.05);Besides,esotropia decreased QOL in domains of somatic symptoms P=0.002 and psychological factors(P=0.023).Students with accommodation insufficiency experienced more symptoms in all domains(P<0.05)except for psychological factors(P=0.07).Increasing in the near point of convergence and accommodation and decreases QOL and increasing accommodative facility increases QOL(all P<0.05).Myopia and astigmatism cause decrease in QOL(both P<0.05),but hyperopic students had better QOL in comparison with others(P<0.05).CONCLUSION:Screening programs and treatment of refractive errors and binocular vision anomalies,especially phoria and accommodative insufficiency,positively impact the QOL and academic achievements of university students.展开更多
In this paper,we have calculated the structural,electronic,and optical properties of chalcogenide stannite Cu_(2)CdSnX4(X=S,Se,Te) materials.The calculations are based on the density functional theory (DFT) method and...In this paper,we have calculated the structural,electronic,and optical properties of chalcogenide stannite Cu_(2)CdSnX4(X=S,Se,Te) materials.The calculations are based on the density functional theory (DFT) method and are performed using the Cambridge sequential total energy package (CASTEP) code included in the Biovia Material Studio 20 software.All optical properties have been studied in a domain that extends energetically from 10 meV to 40 eV.Our results show that Cu_(2)CdSnX4(X=S,Se,Te) stannite exhibits absorption in the visible region,the refractive index decreases with increasing energy,and the refractive index values are n=3.2,3.73 and 3.75 for Cu_(2)CdSnS_(4),Cu_(2)CdSnSe_(4)and Cu_(2)CdSnTe_(4),respectively.They show also high conductivity,which implies that this material is promising for solar cells.These results argue in favor of the use of these materials in various potential applications.The density of state,band structures,and structural properties of Cu_(2)CdSnX4(X=S,Se,and Te) stannite are also studied in this work.展开更多
AIM:To evaluate the visual outcomes of implantable collamer lenses(ICLs)and identify the possible risk factors for ICL axis misalignment,and consequently,repositioning,explanting,or exchanging at a specialized eye hos...AIM:To evaluate the visual outcomes of implantable collamer lenses(ICLs)and identify the possible risk factors for ICL axis misalignment,and consequently,repositioning,explanting,or exchanging at a specialized eye hospital in Saudi Arabia.METHODS:The medical records of 813 eyes with different refractive errors corrected with ICL implantation were identified and included in this single-arm retrospective cohort study.The following data were collected:demographic characteristics,primary diagnosis,preoperative refraction,anterior chamber depth(ACD),white-to-white(WTW)measurement,endothelial cell density(ECD),and axial length.Patients’satisfaction and complaints,and their postoperative refraction,vault depth,and axis alignment with the preoperative target,were reviewed during the postoperative period.Collectively,these data were correlated with symptomatic axis rotation and the need for repositioning,explantation,or exchange due to high or low ICL vaults.RESULTS:Of 813 eyes,27(3.32%),13(1.59%),and 11(1.35%)required ICL repositioning,ICL explantation only without exchange,and ICL explantation with the placement of a new ICL,respectively.The mean follow-up period was 37.5mo.The main cause of explanation or exchange was incorrect WTW measurement in seven(29.17%)eyes,followed by high vault in four(16.56%)eyes.ICL repositioning was required in 27(3.32%)eyes with considerable rotation.Only 2(0.24%)eyes developed cataracts that required ICL removal,and retinal complications were reported in 7(0.86%)eyes.Long-term glaucoma and corneal decompensation were not observed in this cohort.CONCLUSION:With a high safety profile and reversibility,ICL implantation is a good alternative to corneal-based refractive surgery in eyes unsuitable for laser vision correction.The rate of secondary procedures in our study was 6.26%.Old age is a risk factor for secondary surgical interventions in the repositioning group,whereas abnormal vault and toric ICL rotation in the explantation group necessitated subsequent surgical procedures.Overall,ICL implantation demonstrates a good efficacy index and safety profile in patients with diverse refractive errors.展开更多
A plasmonics waveguide structure that consist of a non-through metal–insulator–metal(MIM)waveguide coupled with a D-shaped cavity was designed.And the transmission properties,magnetic field distribution,and refracti...A plasmonics waveguide structure that consist of a non-through metal–insulator–metal(MIM)waveguide coupled with a D-shaped cavity was designed.And the transmission properties,magnetic field distribution,and refractive index sensing functionality were simulated using the finite element method(FEM).A multi-Fano resonance phenomenon was clearly observable in the transmission spectra.The Fano resonances observed in the proposed structure arise from the interaction between the discrete states of the Dshaped resonant cavity and the continuum state of the non-through MIM waveguide.The influence of structural parameters on Fano resonance modulation was investigated through systematic parameter adjustments.Additionally,the refractive index sensing properties,based on the Fano resonance,were investigated by varying the refractive index of the MIM waveguide's insulator layer.A maximum sensitivity and FOM of 1155 RIU/nm and 40 were achieved,respectively.This research opens up new possibilities for designing and exploring high-sensitivity photonic devices,micro-sensors,and innovative on-chip sensing architectures for future applications.展开更多
Based on optofluidics and whispering gallery mode(WGM)theory,here an optofluidic refractive index sensor with microtube-coupled suspended core fiber(SCF)is proposed.It solves the issues of general sensors with microca...Based on optofluidics and whispering gallery mode(WGM)theory,here an optofluidic refractive index sensor with microtube-coupled suspended core fiber(SCF)is proposed.It solves the issues of general sensors with microcavity-coupled fiber taper such as too fragile,unstable performance due to open coupling,poor portability and repeatability,while overcoming the poor performance of low refractive index sensing in general full-package fiber sensors.The sensor only needs a very small amount of liquid sample(about 1.8 nL).The proposed sensor combines the excellent performance of full package,optofluidics and WGM resonator.The resonant characteristics and sensing performance of the sensor are analyzed and discussed by the theoretical simulation.The simulation results indicate that the sensor has a wide refractive index sensing range(1.330-1.700)and good performance.The resonance wavelength shift has a good linear relationship with the liquid refractive index variation.In the low refractive index region,the sensitivity is 222.5-247.5 nm/RIU,Q-factor is 1.03×10^(3) and the detection limit is 3.64×10^(-4) RIU.In the medium and high refractive index regions,the sensitivity is 564.4-846.2 nm/RIU,Q-factor is up to 8.62×10^(4),and the detection limit can be as low as 1.29×10^(-6) RIU.The sensor exhibits a high sensitivity,a high Q-factor and a very low detection limit.展开更多
Blindness affected 45 million people globally in 2021,and moderate to severe vision loss a further 295 million.[1]The most common causes,cataract and uncorrected refractive error,are generally the easiest to treat,and...Blindness affected 45 million people globally in 2021,and moderate to severe vision loss a further 295 million.[1]The most common causes,cataract and uncorrected refractive error,are generally the easiest to treat,and are among the most cost-effective procedures in all of medicine and international development.[1-2]Thus,vision impairment is both extremely common and,in principle,readily manageable.展开更多
AIM:To analyze the two-year visual and refractive outcomes as well as the safety,and efficacy of photorefractive keratectomy(PRK)surgery for myopia.METHODS:In this prospective cohort study,63 eligible patients were re...AIM:To analyze the two-year visual and refractive outcomes as well as the safety,and efficacy of photorefractive keratectomy(PRK)surgery for myopia.METHODS:In this prospective cohort study,63 eligible patients were recruited,including 45 women(71.4%)and 18 men(28.6%).Demographic characteristics along with pre-and post-operative clinical data including visual acuity,refraction,maximum ablation,spherical and cylindrical error,and residual stromal bed(RSB)were evaluated.RESULTS:The mean age of the patients was 35.42±8.16y(range 22 to 55y).The mean spherical and cylindrical error before surgery were-2.23±1.58 D(range-5 to+0.25)and-1.24±0.94 D,respectively(range-3.75 to 0.00).The mean efficacy and safety of PRK surgery at 2y follow-up were 0.98±0.06 and 1.01±0.04 respectively.The lower age was significantly correlated with a higher amount of efficacy index(P<0.001,r=-0.42).Also,the lower amount of preoperative myopia and spherical equivalent(SE)were correlated with a higher safety index(P<0.001,r=-0.44;P<0.001,r=-0.46).CONCLUSION:The two-year efficacy and safety of PRK for the treatment of low myopia is excellent.Younger age and lower amount of refractive error are correlated with higher efficacy and safety indices of the surgery.展开更多
There is limited amount of research on surface plasmon resonance(SPR)sensors with self-referencing capabilities which are based on dielectric gratings.In the short-wavelength range,a metal grating sensor is capable of...There is limited amount of research on surface plasmon resonance(SPR)sensors with self-referencing capabilities which are based on dielectric gratings.In the short-wavelength range,a metal grating sensor is capable of simultaneously measuring liquid refractive index under proposed temperature.A fabricated gold grating is placed on one side of a thin gold film for refractive index measurement,while the other with polydimethylsiloxane(PDMS)is deposited on the other side for temperature measurement.We use finite element analysis to research its sensing characteristics.Due to the high refractive index sensitivity of SPR sensors and thermo-optic coefficient of PDMS,we discovered the maximum spectral sensitivity of the sensor is 564 nm/RIU and-50 pm/℃when the liquid refractive index ranges from 1.30 to 1.40 with temperature ranging from 0℃ to 100℃.Numerical results indicate that there may not be mutual interference between two channels for measuring refractive index and temperature,which reduces the complexity of sensor measurements.展开更多
A D-type photonic crystal fiber(PCF) sensor based on surface plasmon resonance(SPR) principle is designed.In order to excite the SPR effect,a gold film is plated on the open-loop channel of the sensor,the free electro...A D-type photonic crystal fiber(PCF) sensor based on surface plasmon resonance(SPR) principle is designed.In order to excite the SPR effect,a gold film is plated on the open-loop channel of the sensor,the free electrons in a metal are resonated with photons.The structural parameters are fine-tuned and the sensing performance of the sensor is studied.The results show that the maximum spectral sensitivity reaches 18 000 nm/RIU in the refractive index range of 1.24—1.32,and the maximum resolution is 5.56×10^(-6) RIU.The novel structure with high sensitivity and low refractive index provides a new perspective for fluid density detection.展开更多
文摘An approximate analytic model is presented to describe spatial structure of refracted electromagnetic field arising at oblique incidence of a Gaussian beam on a plane boundary of an absorbing homogeneous medium. The analytic solution is obtained by asymptotic approximation of a Fourier field integral under the condition of great beam width in comparison with a wavelength (the geometrical-optics approximation). This model can be used also for approximate simulation of refracted field in the cases of beam incidence near the critical angle on transparent or absorbing (amplifying) refracting medium, if one artificially introduces the additional absorption (amplification), whose value is proportional to the ratio of the wavelength and the effective beam width. It is shown that the analytic model reflects the general features of refracted field at total internal reflection.
基金Supported by the"10th Five-Year"National Science and Technology Plan of China(Grant No.2003BA613A-09)China Innovation Foundation of Petroleum Technology for Young and Middle-Aged Scholars(Grant No.03E7018)
文摘Three-component seismic exploration through P-wave source and three-component geophone is an effective technique used in complicated reservoir exploration.In three-component seismic exploration data processing,one of the difficulties is static correction of converted wave.This paper analyzes propagation characteristics of non-converted and converted refracted waves,and discovers a favor-able condition for the formation of converted refracted wave,i.e.the velocity of overlaying medium S wave is much lower than that of underlying medium S wave.In addition,the paper proposes the static correction method of converted wave based on PPS converted refracted wave,and processes the real three-component seismic data with better results of static correction of converted wave.
基金Supported by Ongoing Research Funding Program(ORFFT-2025-054-1),King Saud University,Riyadh,Saudi Arabia.
文摘AIM:To evaluate the efficacy of the total computer vision syndrome questionnaire(CVS-Q)score as a predictive tool for identifying individuals with symptomatic binocular vision anomalies and refractive errors.METHODS:A total of 141 healthy computer users underwent comprehensive clinical visual function assessments,including evaluations of refractive errors,accommodation(amplitude of accommodation,positive relative accommodation,negative relative accommodation,accommodative accuracy,and accommodative facility),and vergence(phoria,positive and negative fusional vergence,near point of convergence,and vergence facility).Total CVS-Q scores were recorded to explore potential associations between symptom scores and the aforementioned clinical visual function parameters.RESULTS:The cohort included 54 males(38.3%)with a mean age of 23.9±0.58y and 87 age-matched females(61.7%)with a mean age of 23.9±0.53y.The multiple regression model was statistically significant[R²=0.60,F=13.28,degrees of freedom(DF=17122,P<0.001].This indicates that 60%of the variance in total CVS-Q scores(reflecting reported symptoms)could be explained by four clinical measurements:amplitude of accommodation,positive relative accommodation,exophoria at distance and near,and positive fusional vergence at near.CONCLUSION:The total CVS-Q score is a valid and reliable tool for predicting the presence of various nonstrabismic binocular vision anomalies and refractive errors in symptomatic computer users.
基金Supported by Vision International Eye Missions-USA,“One Drop for All”,Italy,and Private Donors in the Netherlands.
文摘AIM:To ascertain the pattern of ocular morbidity in a population of primary school children in rural Kenya as it is a prerequisite for planning effective preventive and therapeutic strategies.METHODS:A cross-sectional survey of ocular symptoms and clinical eye examinations were performed in a sample of 35 rural primary schools in the semi-arid region of Kajiado West sub-county in S.W.Kenya,amongst a seminomadic tribe(Maasai).Students in Grades 1-8 were included.Visual acuity was measured using the Snellen“tumbling E”chart at 6 m.Children with symptoms of refractive error underwent non-cycloplegic refraction.RESULTS:A total of 2036 children(1084 males)between the ages of 4-20y were examined.Conjunctival actinic changes were present in 22%(442/2036).Nine cases were seen with a potential squamous carcinoma.No overt classical ocular signs of vitamin A deficiency were noted,although 181(8.9%)children complained of nyctalopia.Three hundred thirty-six(16.5%)children had a visual acuity worse than 6/12 in either eye,were unable to read N10 near text at 40 cm or had symptoms suggestive of refractive error.Refractive data led to an estimate of hyperopia of+1.00 D or more in 3.9%and of myopia of-0.50 D or more in either eye in 3.0%of the study population.CONCLUSION:Solar exposure-and dust-related conjunctival pathology is common.As this may develop into potentially sight-or even life-threatening conditions,it warrants further study,and preventive strategies may be needed.Complaints of nyctalopia were common and could suggest vitamin A deficiency.The prevalence of refractive errors is low in this rural African population.
基金Supported by the Zhejiang Medical Health Science and Technology Project(No.2021KY217)the Basic Public Welfare Research Project of Wenzhou Municipal Science and Technology Bureau(No.2024Y1221).
文摘AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs.
文摘Dear Editor,We present this case report which discusses a patient who underwent flap amputation after repeated attempts to resolve persistent and severe epithelial ingrowth following laser-assisted in situ keratomileusis(LASIK)surgery.Epithelial ingrowth is a known complication of LASIK surgery,typically manageable with minimal measures.However,severe cases may necessitate more aggressive interventions,such as flap amputation[1].LASIK is a widely performed refractive surgery with high success rates and excellent visual outcome[2].
文摘Ocular biological characteristics and refractive errors in children with unilateral congenital ptosis Yu-Ying Sun,Bing-Ying Lin,Zhen Mao,Xuan-Wei Liang,Cui-Yu Zhang,Dan-Ping Huang,Yao Ni,Zuo-Hong Li Int J Ophthalmol 2025;18(4):691-698.DOI:10.18240/ijo.2025.04.16 The author requests to change the authorship and affiliations as follows.
基金financial support by the National Key Research and Development Program of China(No.2023YFB4605400)the National Natural Science Foundation of China(No.12472152)the Department of Science and Technology of Guangdong Province(No.2019QN01Z438)。
文摘Gradient refractive index(GRIN)metalenses are increasingly valued in high-frequency communication due to their exceptional radiation performance.Ceramics with high dielectric constants and low dielectric losses are ideal candidates for GRIN metalenses.Digital light processing(DLP)3D printing provides a feasible and efficient approach for manufacturing ceramic GRIN metalenses.However,the scattering of ultraviolet(UV)light by ceramic particles in the slurry reduces the printing accuracy of DLP technology,making it difficult to achieve the intricate structural features required for GRIN metalenses in high-frequency communication.In this work,we propose an approach to improve printing accuracy by optimizing the ceramic slurry composition and implementing a dimensional compensation design strategy.Utilizing geometric optics and the S-parameter inversion method,we design a GRIN metalens consisting of two distinct types of subwavelength unit cells(Y-shaped and circular hole geometries)with a minimum feature size of 160μm.Through a refined slurry formulation and precise design parameter compensation,high-fidelity ceramic GRIN metalenses are successfully fabricated.The fabricated metalens exhibits a maximum gain enhancement of 18.4 dBi and a deflection angle of±30°over a bandwidth of 37.84% in the W-band(75-110 GHz).The highly directional far-field beam radiation and efficient beam steering capabilities highlight the potential of ceramic GRIN metalenses for applications in satellite communications,radar systems,and other high-frequency technologies.
基金Project supported by the National Natural Science Foundation of China(Grant No.12175107)the Qing Lan Project of Jiangsu Province+2 种基金the Hua Li Talents Program of Nanjing University of PostsTelecommunications,Natural Science Foundation of Nanjing Vocational University of Industry Technology(Grant No.YK22-02-08)the Fund from the Research Center of Industrial Perception and Intelligent Manufacturing Equipment Engineering of Jiangsu Province,China(Grant No.ZK21-05-09)。
文摘Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)sensors.Among them,the traditional surface plasmon polariton(SPP)based on noble metals limits its application beyond the near-infrared(IR)regime due to the large negative permittivity and optical losses.In this contribution,we theoretically proposed a highly sensitive PSHE sensor with the structure of Ge prism-SiC-Si:InAs-sensing medium,by taking advantage of the hybrid surface plasmon phonon polariton(SPPhP)in mid-IR regime.Here,heavily Si-doped InAs(Si:InAs)and SiC excite the SPP and surface phonon polariton(SPhP),and the hybrid SPPhP is realized in this system.More importantly,the designed PSHE sensor based on this SPPhP mechanism achieves the multi-stage RI measurements from 1.00025-1.00225 to 1.70025-1.70225,and the maximal intensity sensitivity and angle sensitivity can be up to 9.4×10^(4)μm/RIU and245°/RIU,respectively.These findings provide a new pathway for the enhancement of PSHE in mid-IR regime,and offer new opportunities to develop highly sensitive RI sensors in multi-scenario applications,such as harmful gas monitoring and biosensing.
基金support by National Natural Science Foundation of China (Nos. 51606158, 12104402)
文摘Fiber-optic sensing technology has the advantages of passivity, anti-electromagnetic interference, longdistancemeasurement, high sensitivity and high accuracy, small size, and adaptability to harsh environments such ashigh-vacuum, high-pressure, and strong magnetic fields compared with the traditional electrical sensing technology.However, with the increasing application requirements, how to further improve the sensitivity of fiber-optic sensors,extend the detection limit and improve the maintenance-free capability has become one of the core issues of thecurrent research. This paper reviews the principle, preparation, and application of fiber-optic microstructured sensingbased on abrupt field type. It specifically outlines the development and applications of micro-nano optical fibers,photonic crystal optical fibers, optical fiber gratings and structured optical fibers, and lists the main preparationmethods of two types of micro-nano optical fibers from the basic theory of optical fiber microstructured sensordevices.
基金Natural Science Foundation of Fujian Province(No.2024J011611)Natural Science Foundation of Nanping City(No.N2021J020)。
文摘AIM:To evaluate the visual function and optical quality in adults aged 80y and older following the bilateral implantation of zonal refractive multifocal intraocular lens(IOL,LS-313 MF30).METHODS:A single-center,non-randomized,prospective clinical trial was conducted,involving cataract patients aged 80 y and older.Patients received bilateral implantation of the LS-313 MF30 or CT Asphina 409MP,based on personal preference.Postoperative assessments included uncorrected and corrected visual acuity at distance,intermediate,and near ranges,as well as defocus curve.Subjective evaluations were performed using the visual function(VF-14)questionnaire,spectacle independence rates,and patient satisfaction surveys.Photic phenomena such as glare,halos,and starbursts were also analyzed.RESULTS:The MF30 group(16 eyes from 8 participants,85.38±2.56 y)exhibited superior uncorrected and corrected intermediate and near visual acuity compared to the 409MP group(26 eyes from 13 participants,85.77±2.20 y),while distance visual acuity was comparable between groups.The defocus curve of the MF30 group revealed two peaks at 0.00 D and-3.00 D,indicating a broader depth of focus.Patients in the MF30 group reported higher rates of spectacle independence and greater satisfaction.While photic phenomena such as glare(28.6%vs 18.5%,P=0.584),starburst(9.5%vs 3.7%,P=0.567)and halos(23.8%vs 11.11%,P=0.438)were more prevalent in the MF30 group,they were generally mild and did not significantly impact daily activities.CONCLUSION:Zonal refractive multifocal IOLs provide elderly patients with improved distance and near vision,greater spectacle independence,and greater satisfaction.Although photic phenomena were slightly more frequent with MF30,they are generally reported as non-disruptive and do not affect their daily life compared to monofocal IOLs.
文摘AIM:To evaluate the effects of refractive errors and binocular vision anomalies on the quality of life(QOL)of university students.METHODS:This cross-sectional analytical study was conducted on university students using simple random sampling.Objective refraction,ocular alignment,vergence and accommodative performance were measured and assessed in all participants.Data on QOL were collected using the College of Optometrists in Vision Development-Quality of Life(COVD-QOL)Questionnaire.The effect of mentioned parameters on the QOL were evaluated.RESULTS:Totally 726 students with mean age of 21.35±1.88y were evaluated in this study,51.5%of whom were female.Esophoria was caused significantly lower QOL in the domains of somatic symptoms and occupationalphysical symptoms(P<0.05);Besides,esotropia decreased QOL in domains of somatic symptoms P=0.002 and psychological factors(P=0.023).Students with accommodation insufficiency experienced more symptoms in all domains(P<0.05)except for psychological factors(P=0.07).Increasing in the near point of convergence and accommodation and decreases QOL and increasing accommodative facility increases QOL(all P<0.05).Myopia and astigmatism cause decrease in QOL(both P<0.05),but hyperopic students had better QOL in comparison with others(P<0.05).CONCLUSION:Screening programs and treatment of refractive errors and binocular vision anomalies,especially phoria and accommodative insufficiency,positively impact the QOL and academic achievements of university students.
基金supported by the University Sultan Moulay Slimane,Beni Mellal,Morocco。
文摘In this paper,we have calculated the structural,electronic,and optical properties of chalcogenide stannite Cu_(2)CdSnX4(X=S,Se,Te) materials.The calculations are based on the density functional theory (DFT) method and are performed using the Cambridge sequential total energy package (CASTEP) code included in the Biovia Material Studio 20 software.All optical properties have been studied in a domain that extends energetically from 10 meV to 40 eV.Our results show that Cu_(2)CdSnX4(X=S,Se,Te) stannite exhibits absorption in the visible region,the refractive index decreases with increasing energy,and the refractive index values are n=3.2,3.73 and 3.75 for Cu_(2)CdSnS_(4),Cu_(2)CdSnSe_(4)and Cu_(2)CdSnTe_(4),respectively.They show also high conductivity,which implies that this material is promising for solar cells.These results argue in favor of the use of these materials in various potential applications.The density of state,band structures,and structural properties of Cu_(2)CdSnX4(X=S,Se,and Te) stannite are also studied in this work.
文摘AIM:To evaluate the visual outcomes of implantable collamer lenses(ICLs)and identify the possible risk factors for ICL axis misalignment,and consequently,repositioning,explanting,or exchanging at a specialized eye hospital in Saudi Arabia.METHODS:The medical records of 813 eyes with different refractive errors corrected with ICL implantation were identified and included in this single-arm retrospective cohort study.The following data were collected:demographic characteristics,primary diagnosis,preoperative refraction,anterior chamber depth(ACD),white-to-white(WTW)measurement,endothelial cell density(ECD),and axial length.Patients’satisfaction and complaints,and their postoperative refraction,vault depth,and axis alignment with the preoperative target,were reviewed during the postoperative period.Collectively,these data were correlated with symptomatic axis rotation and the need for repositioning,explantation,or exchange due to high or low ICL vaults.RESULTS:Of 813 eyes,27(3.32%),13(1.59%),and 11(1.35%)required ICL repositioning,ICL explantation only without exchange,and ICL explantation with the placement of a new ICL,respectively.The mean follow-up period was 37.5mo.The main cause of explanation or exchange was incorrect WTW measurement in seven(29.17%)eyes,followed by high vault in four(16.56%)eyes.ICL repositioning was required in 27(3.32%)eyes with considerable rotation.Only 2(0.24%)eyes developed cataracts that required ICL removal,and retinal complications were reported in 7(0.86%)eyes.Long-term glaucoma and corneal decompensation were not observed in this cohort.CONCLUSION:With a high safety profile and reversibility,ICL implantation is a good alternative to corneal-based refractive surgery in eyes unsuitable for laser vision correction.The rate of secondary procedures in our study was 6.26%.Old age is a risk factor for secondary surgical interventions in the repositioning group,whereas abnormal vault and toric ICL rotation in the explantation group necessitated subsequent surgical procedures.Overall,ICL implantation demonstrates a good efficacy index and safety profile in patients with diverse refractive errors.
文摘A plasmonics waveguide structure that consist of a non-through metal–insulator–metal(MIM)waveguide coupled with a D-shaped cavity was designed.And the transmission properties,magnetic field distribution,and refractive index sensing functionality were simulated using the finite element method(FEM).A multi-Fano resonance phenomenon was clearly observable in the transmission spectra.The Fano resonances observed in the proposed structure arise from the interaction between the discrete states of the Dshaped resonant cavity and the continuum state of the non-through MIM waveguide.The influence of structural parameters on Fano resonance modulation was investigated through systematic parameter adjustments.Additionally,the refractive index sensing properties,based on the Fano resonance,were investigated by varying the refractive index of the MIM waveguide's insulator layer.A maximum sensitivity and FOM of 1155 RIU/nm and 40 were achieved,respectively.This research opens up new possibilities for designing and exploring high-sensitivity photonic devices,micro-sensors,and innovative on-chip sensing architectures for future applications.
基金supported by the National Natural Science Foundation of China(No.12174199)the Wanjing Horizontal Research and Development Fund for Nature(No.HJ1060319960015).
文摘Based on optofluidics and whispering gallery mode(WGM)theory,here an optofluidic refractive index sensor with microtube-coupled suspended core fiber(SCF)is proposed.It solves the issues of general sensors with microcavity-coupled fiber taper such as too fragile,unstable performance due to open coupling,poor portability and repeatability,while overcoming the poor performance of low refractive index sensing in general full-package fiber sensors.The sensor only needs a very small amount of liquid sample(about 1.8 nL).The proposed sensor combines the excellent performance of full package,optofluidics and WGM resonator.The resonant characteristics and sensing performance of the sensor are analyzed and discussed by the theoretical simulation.The simulation results indicate that the sensor has a wide refractive index sensing range(1.330-1.700)and good performance.The resonance wavelength shift has a good linear relationship with the liquid refractive index variation.In the low refractive index region,the sensitivity is 222.5-247.5 nm/RIU,Q-factor is 1.03×10^(3) and the detection limit is 3.64×10^(-4) RIU.In the medium and high refractive index regions,the sensitivity is 564.4-846.2 nm/RIU,Q-factor is up to 8.62×10^(4),and the detection limit can be as low as 1.29×10^(-6) RIU.The sensor exhibits a high sensitivity,a high Q-factor and a very low detection limit.
文摘Blindness affected 45 million people globally in 2021,and moderate to severe vision loss a further 295 million.[1]The most common causes,cataract and uncorrected refractive error,are generally the easiest to treat,and are among the most cost-effective procedures in all of medicine and international development.[1-2]Thus,vision impairment is both extremely common and,in principle,readily manageable.
文摘AIM:To analyze the two-year visual and refractive outcomes as well as the safety,and efficacy of photorefractive keratectomy(PRK)surgery for myopia.METHODS:In this prospective cohort study,63 eligible patients were recruited,including 45 women(71.4%)and 18 men(28.6%).Demographic characteristics along with pre-and post-operative clinical data including visual acuity,refraction,maximum ablation,spherical and cylindrical error,and residual stromal bed(RSB)were evaluated.RESULTS:The mean age of the patients was 35.42±8.16y(range 22 to 55y).The mean spherical and cylindrical error before surgery were-2.23±1.58 D(range-5 to+0.25)and-1.24±0.94 D,respectively(range-3.75 to 0.00).The mean efficacy and safety of PRK surgery at 2y follow-up were 0.98±0.06 and 1.01±0.04 respectively.The lower age was significantly correlated with a higher amount of efficacy index(P<0.001,r=-0.42).Also,the lower amount of preoperative myopia and spherical equivalent(SE)were correlated with a higher safety index(P<0.001,r=-0.44;P<0.001,r=-0.46).CONCLUSION:The two-year efficacy and safety of PRK for the treatment of low myopia is excellent.Younger age and lower amount of refractive error are correlated with higher efficacy and safety indices of the surgery.
基金supported by the National Natural Science Foundation of China(No.52276094)the Education Project of Hunan Provincial Department(Nos.20B602 and 22C0112)+2 种基金the Industry University Education Cooperation Project(No.230803117185211)the Research Project on Teaching Reform in Ordinary Undergraduate Universities in Hunan Province(No.202401000142)the Natural Science Foundation of Hunan Province(No.2020JJ4935)。
文摘There is limited amount of research on surface plasmon resonance(SPR)sensors with self-referencing capabilities which are based on dielectric gratings.In the short-wavelength range,a metal grating sensor is capable of simultaneously measuring liquid refractive index under proposed temperature.A fabricated gold grating is placed on one side of a thin gold film for refractive index measurement,while the other with polydimethylsiloxane(PDMS)is deposited on the other side for temperature measurement.We use finite element analysis to research its sensing characteristics.Due to the high refractive index sensitivity of SPR sensors and thermo-optic coefficient of PDMS,we discovered the maximum spectral sensitivity of the sensor is 564 nm/RIU and-50 pm/℃when the liquid refractive index ranges from 1.30 to 1.40 with temperature ranging from 0℃ to 100℃.Numerical results indicate that there may not be mutual interference between two channels for measuring refractive index and temperature,which reduces the complexity of sensor measurements.
基金supported by the Natural Science Foundation of Tianjin City (No.19JCYBJC17000)the National Natural Science Foundation of China (No.11905159)。
文摘A D-type photonic crystal fiber(PCF) sensor based on surface plasmon resonance(SPR) principle is designed.In order to excite the SPR effect,a gold film is plated on the open-loop channel of the sensor,the free electrons in a metal are resonated with photons.The structural parameters are fine-tuned and the sensing performance of the sensor is studied.The results show that the maximum spectral sensitivity reaches 18 000 nm/RIU in the refractive index range of 1.24—1.32,and the maximum resolution is 5.56×10^(-6) RIU.The novel structure with high sensitivity and low refractive index provides a new perspective for fluid density detection.
