Laser display technology is the most promising display technology in the market and is widely used in many fields. However, laser speckle has been troubling the application and expansion of this technology in some fie...Laser display technology is the most promising display technology in the market and is widely used in many fields. However, laser speckle has been troubling the application and expansion of this technology in some fields. In order to better evaluate the speckle, speckle measurement methods must be studied. In this study, a dynamic measurement method for laser speckles is proposed according to the optical superposition characteristics of speckle, which can reduce the influence of non-coherent factors on the speckle measurement results. The feasibility of the dynamic speckle measurement method is verified by designing an experimental scheme.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
Flexible laser display is a critical component for an information output port in next-generation wearable devices.So far,the lack of appropriate display panels capable of providing sustained operation under rigorous m...Flexible laser display is a critical component for an information output port in next-generation wearable devices.So far,the lack of appropriate display panels capable of providing sustained operation under rigorous mechanical conditions impedes the development of flexible laser displays with high reliability.Owing to the multiple scattering feedback mechanism,random lasers render high mechanical flexibility to withstand deformation,thus making them promising candidates for flexible display planes.However,the inability to obtain pixelated random laser arrays with highly ordered emissive geometries hinders the application of flexible laser displays in the wearable device.Here,for the first time,we demonstrate a mass fabrication strategy of full-color random laser arrays for flexible display panels.The feedback closed loops can be easily fulfilled in the pixels by multiple scatterings to generate durative random lasing.Due to the sustained operation of random laser,the display performance was well-maintained under mechanical deformations,and as a result,a flexible laser display panel was achieved.Our finding will provide a guidance for the development of flexible laser displays and laser illumination devices.展开更多
Laser displays,benefiting from the characteristic merits of lasers,have led to the revolution of next-generation display technologies owing to their superior color expression.However,the acquisition of pixelated laser...Laser displays,benefiting from the characteristic merits of lasers,have led to the revolution of next-generation display technologies owing to their superior color expression.However,the acquisition of pixelated laser arrays as self-emissive panels for flat-panel laser displays remains challenging.Liquid crystal(LC)materials with excellent processability and optoelectronic properties offer considerable potential for the construction of highly ordered multicolor laser arrays.Here,we demonstrate flat-panel laser displays on LC microlaser pixel arrays through a microtemplate-assisted inkjet printing method.Individual organic red-green-blue(RGB)microlaser pixel arrays were obtained by doping dyes into LCs with photonic band edges to obtain single-mode RGB lasing,leading to a much broader color gamut,compared with the standard RGB color space.Then we acquired periodically patterned RGB pixel matrices by positioning LC microlasers precisely into highly ordered arrays,according to the well-organized geometry of the microtemplates.Subsequently,we demonstrated full-color flat-panel laser displays using the LC microlaser pixel matrices as self-emissive panels.These results provide valuable enlightenment for the construction of next-generation flat-panel laser display devices.展开更多
Lenticular printing technique provides a promising way to realize stereoscopic displays,especially,when microscopic optical structures are integrated into light-emitting materials/devices.Here,we fabricated large-area...Lenticular printing technique provides a promising way to realize stereoscopic displays,especially,when microscopic optical structures are integrated into light-emitting materials/devices.Here,we fabricated large-area periodic structures with a spatial resolution at a wavelength scale from hybrid perovskite materials via a space-confined solution growth method.It takes advantages of both high refractive index contrast and high luminescence brightness,which allows the optical modulation on not only the reflection of illumination,but also the light emission from hybrid perovskites.The distributed feedback within these periodic structures significantly improves the degree of polarization and directionality of laser actions while their threshold is also reduced.These findings enable us to present a prototype of lenticular printing laser displays that vary emission colors at different view angles,which may find applications in creating high-resolution and high-contrast holographical images.展开更多
Laser phosphor display(LPD)technology has attained considerable attention due to its high brightness,wide-gamut,and non-speckle characters.However,it is challenging to develop laser-resistant bulk luminescent material...Laser phosphor display(LPD)technology has attained considerable attention due to its high brightness,wide-gamut,and non-speckle characters.However,it is challenging to develop laser-resistant bulk luminescent materials with narrow-band emissions for LPD applications.Herein,we present a general strategy to fabricate stable phosphor-glass composites(PGCs)containing commercial red-emitting K_(2)SiF_(6):Mn^(4+)(KSF:Mn^(4+))and green-emitting β-SiAlON:Eu^(2+)with high internal quantum efficiencies of 94.6%and 87.8%.Thereupon,“phosphor wheels”of the two PGCs achieve high luminous flux and efficiency for KSF:Mn-PGC(684 lm,21 lm W^(−1) mm^(−1))andβ-SiAlON:Eu-PGC(4770 lm,172 lm W^(−1) mm^(−1)),respectively,by mitigating thermal accumulation.Finally,we integrate these two PGCs into a patterned phosphor wheel,which covers 125%of the Rec.709 standard,far exceeding that of the present YAG:Ce-based laser light sources(103%).Our work paves the way for adapting commercial phosphors in bulk PGC materials to improve their stability and further promote LPD development and new types of display applications.展开更多
Laser phosphor display technology plays an important role in advanced display projection;however,it is a challenge in maintaining excellent color accuracy under high brightness due to the lack of red spectrum.Here,red...Laser phosphor display technology plays an important role in advanced display projection;however,it is a challenge in maintaining excellent color accuracy under high brightness due to the lack of red spectrum.Here,red-emitting Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)ceramics as the phosphor wheel have been optimized in chemical compositions and texture orientation.The textured Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)ceramics have high transparency and spot limiting ability,accordingly,the ceramic wheel outputs 1,184 lm of ultra-bright red light under 50 W/mm^(2) laser power density.Moreover,the red spectral utilization(over 600 nm)of textured Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)ceramics is 2.17 times that of traditional Y_(3)Al_(5)O_(12):Ce^(3+)phosphor wheel.The red-emitting textured Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)cordierite ceramic herein enables an improved light-color saturation experience,and it is potential in the next-generation laser phosphor display applications.展开更多
We design a 645 nm laser diode(LD)with a narrow vertical beam divergence angle based on the mode expansion layer.The vertical beam divergence of 10.94°at full width at half-maximum is realized under 1.5 A continu...We design a 645 nm laser diode(LD)with a narrow vertical beam divergence angle based on the mode expansion layer.The vertical beam divergence of 10.94°at full width at half-maximum is realized under 1.5 A continuous-wave operation,which is the smallest vertical beam divergence for such an LD based on the mode expansion layer,to the best of our knowledge.The threshold current and output power are 1.07 A and 0.94 W,limited by the thermal rollover for the 100μm wide and 1500μm long broad area laser,and the slope efficiency is 0.71 W/A.The low coherence device is fabricated with the speckle contrast of 3.6%and good directional emission.Such 645 nm LDs have promising applications in laser display.展开更多
In this paper,a solution for speckle reduction using phase plate array(PPA)and lens array(LA)in a motionless way is proposed.The specially designed PPA is composed of sub-phase plates,which are constituted by phase pa...In this paper,a solution for speckle reduction using phase plate array(PPA)and lens array(LA)in a motionless way is proposed.The specially designed PPA is composed of sub-phase plates,which are constituted by phase patterns formed by Hadamard sub-matrices.Each component of the proposed optical system should satisfy the stated relationships.The incident laser beam will be incoherent after passing through PPA,and superpose on the screen under the action of LA and main lens.Speckle reduction can be achieved by the averaging of the incoherent speckle patterns.Because of abandoning the mechanical movement,it will be suitable for laser displays and images.展开更多
基金supported by the National Natural Science Foundation of China (No.62076160)the Natural Science Foundation of Shanghai (No.21ZR1424700)。
文摘Laser display technology is the most promising display technology in the market and is widely used in many fields. However, laser speckle has been troubling the application and expansion of this technology in some fields. In order to better evaluate the speckle, speckle measurement methods must be studied. In this study, a dynamic measurement method for laser speckles is proposed according to the optical superposition characteristics of speckle, which can reduce the influence of non-coherent factors on the speckle measurement results. The feasibility of the dynamic speckle measurement method is verified by designing an experimental scheme.
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financially supported by the Ministry of Science and Technology of China(2017YFA0204502)the National Natural Science Foundation of China(21790364)。
文摘Flexible laser display is a critical component for an information output port in next-generation wearable devices.So far,the lack of appropriate display panels capable of providing sustained operation under rigorous mechanical conditions impedes the development of flexible laser displays with high reliability.Owing to the multiple scattering feedback mechanism,random lasers render high mechanical flexibility to withstand deformation,thus making them promising candidates for flexible display planes.However,the inability to obtain pixelated random laser arrays with highly ordered emissive geometries hinders the application of flexible laser displays in the wearable device.Here,for the first time,we demonstrate a mass fabrication strategy of full-color random laser arrays for flexible display panels.The feedback closed loops can be easily fulfilled in the pixels by multiple scatterings to generate durative random lasing.Due to the sustained operation of random laser,the display performance was well-maintained under mechanical deformations,and as a result,a flexible laser display panel was achieved.Our finding will provide a guidance for the development of flexible laser displays and laser illumination devices.
基金supported financially by the Ministry of Science and Technology of China(no.2017YFA0204502)the National Natural Science Foundation of China(grant nos.21533013 and 21790364).
文摘Laser displays,benefiting from the characteristic merits of lasers,have led to the revolution of next-generation display technologies owing to their superior color expression.However,the acquisition of pixelated laser arrays as self-emissive panels for flat-panel laser displays remains challenging.Liquid crystal(LC)materials with excellent processability and optoelectronic properties offer considerable potential for the construction of highly ordered multicolor laser arrays.Here,we demonstrate flat-panel laser displays on LC microlaser pixel arrays through a microtemplate-assisted inkjet printing method.Individual organic red-green-blue(RGB)microlaser pixel arrays were obtained by doping dyes into LCs with photonic band edges to obtain single-mode RGB lasing,leading to a much broader color gamut,compared with the standard RGB color space.Then we acquired periodically patterned RGB pixel matrices by positioning LC microlasers precisely into highly ordered arrays,according to the well-organized geometry of the microtemplates.Subsequently,we demonstrated full-color flat-panel laser displays using the LC microlaser pixel matrices as self-emissive panels.These results provide valuable enlightenment for the construction of next-generation flat-panel laser display devices.
基金financially supported by the Ministry of Science and Technology of China(2018YFA0704802,2017YFA0204502)the National Natural Science Foundation of China(21873105)。
文摘Lenticular printing technique provides a promising way to realize stereoscopic displays,especially,when microscopic optical structures are integrated into light-emitting materials/devices.Here,we fabricated large-area periodic structures with a spatial resolution at a wavelength scale from hybrid perovskite materials via a space-confined solution growth method.It takes advantages of both high refractive index contrast and high luminescence brightness,which allows the optical modulation on not only the reflection of illumination,but also the light emission from hybrid perovskites.The distributed feedback within these periodic structures significantly improves the degree of polarization and directionality of laser actions while their threshold is also reduced.These findings enable us to present a prototype of lenticular printing laser displays that vary emission colors at different view angles,which may find applications in creating high-resolution and high-contrast holographical images.
基金supported by the National Natural Science Foundation of China(52425206)the Fundamental Research Funds for the Central Universities(2024ZYGXZR004)。
文摘Laser phosphor display(LPD)technology has attained considerable attention due to its high brightness,wide-gamut,and non-speckle characters.However,it is challenging to develop laser-resistant bulk luminescent materials with narrow-band emissions for LPD applications.Herein,we present a general strategy to fabricate stable phosphor-glass composites(PGCs)containing commercial red-emitting K_(2)SiF_(6):Mn^(4+)(KSF:Mn^(4+))and green-emitting β-SiAlON:Eu^(2+)with high internal quantum efficiencies of 94.6%and 87.8%.Thereupon,“phosphor wheels”of the two PGCs achieve high luminous flux and efficiency for KSF:Mn-PGC(684 lm,21 lm W^(−1) mm^(−1))andβ-SiAlON:Eu-PGC(4770 lm,172 lm W^(−1) mm^(−1)),respectively,by mitigating thermal accumulation.Finally,we integrate these two PGCs into a patterned phosphor wheel,which covers 125%of the Rec.709 standard,far exceeding that of the present YAG:Ce-based laser light sources(103%).Our work paves the way for adapting commercial phosphors in bulk PGC materials to improve their stability and further promote LPD development and new types of display applications.
基金This research was supported by National Natural Science Foundations of China(51972118)the Fundamental Research Funds for the Central Universities(2023ZYGXZR002)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X137).
文摘Laser phosphor display technology plays an important role in advanced display projection;however,it is a challenge in maintaining excellent color accuracy under high brightness due to the lack of red spectrum.Here,red-emitting Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)ceramics as the phosphor wheel have been optimized in chemical compositions and texture orientation.The textured Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)ceramics have high transparency and spot limiting ability,accordingly,the ceramic wheel outputs 1,184 lm of ultra-bright red light under 50 W/mm^(2) laser power density.Moreover,the red spectral utilization(over 600 nm)of textured Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)ceramics is 2.17 times that of traditional Y_(3)Al_(5)O_(12):Ce^(3+)phosphor wheel.The red-emitting textured Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)cordierite ceramic herein enables an improved light-color saturation experience,and it is potential in the next-generation laser phosphor display applications.
基金supported in part by the National Key R&D Program of China(Nos.2016YFB0401804 and 2016YFA0301102)the National Natural Science Foundation of China(Nos.91850206 and 62075213)。
文摘We design a 645 nm laser diode(LD)with a narrow vertical beam divergence angle based on the mode expansion layer.The vertical beam divergence of 10.94°at full width at half-maximum is realized under 1.5 A continuous-wave operation,which is the smallest vertical beam divergence for such an LD based on the mode expansion layer,to the best of our knowledge.The threshold current and output power are 1.07 A and 0.94 W,limited by the thermal rollover for the 100μm wide and 1500μm long broad area laser,and the slope efficiency is 0.71 W/A.The low coherence device is fabricated with the speckle contrast of 3.6%and good directional emission.Such 645 nm LDs have promising applications in laser display.
文摘In this paper,a solution for speckle reduction using phase plate array(PPA)and lens array(LA)in a motionless way is proposed.The specially designed PPA is composed of sub-phase plates,which are constituted by phase patterns formed by Hadamard sub-matrices.Each component of the proposed optical system should satisfy the stated relationships.The incident laser beam will be incoherent after passing through PPA,and superpose on the screen under the action of LA and main lens.Speckle reduction can be achieved by the averaging of the incoherent speckle patterns.Because of abandoning the mechanical movement,it will be suitable for laser displays and images.
