Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extens...Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extensive attention due to their advantages of small size,high multiplexing efficiency,convenient mass production,and low cost.An RGB beam combiner based on directional couplers is designed,with a core-cladding relative refractive index difference of 0.75%.The RGB beam combiner is optimized from the perspective of parameter optimization.Using the beam propagation method(BPM),the relationship between the performance of the RGB beam combiner and individual parameters is studied,achieving preliminary optimization of the device’s performance.The key parameters of the RGB beam combiner are optimized using the entropy weight-technique for order preference by similarity to an ideal solution TOPSIS method,establishing the optimal parameter scheme and further improving the device’s performance indicators.The results show that after optimization,the multiplexing efficiencies for red,green,and blue lights,as well as the average multiplexing efficiency,reached 99.17%,99.76%,96.63%and 98.52%,respectively.The size of the RGB beam combiner is 4.768 mm×0.062 mm.展开更多
Improved all-optical OR gates are proposed, using a novel fiber nonlinearity-based technique, based on the principles of combined Brillouin gain and loss in a polarization-maintaining fiber （PMF）. Switching contrast...Improved all-optical OR gates are proposed, using a novel fiber nonlinearity-based technique, based on the principles of combined Brillouin gain and loss in a polarization-maintaining fiber （PMF）. Switching contrasts are simulated to be between 82.4%-83.6%, for two respective configurations, and switching time is comparable to the phonon relaxation time in stimulated Brillouin scattering （SBS）.展开更多
In this paper,we have proposed a hybrid optical wavelength demultiplexer and power combiner for a hybrid timeand wavelength-division multiplexing(TWDM)passive optical network(PON),i.e.,a single passive optical device ...In this paper,we have proposed a hybrid optical wavelength demultiplexer and power combiner for a hybrid timeand wavelength-division multiplexing(TWDM)passive optical network(PON),i.e.,a single passive optical device that functions as a 1×N wavelength demultiplexer for distributing the downstream signal in multiple wavelengths from the optical line terminal(OLT)to the N optical network units(ONUs),and simultaneously as an N×1 power combiner for collecting the upstream signal in the same wavelength from the N ONUs to the OLT.Through a design example of a 32 channel hybrid optical wavelength demultiplexer and power combiner on the silicon-on-insulator platform,our numerical simulation result shows that the insertion loss and adjacent channel crosstalk of the downstream wavelength demultiplexer are as low as 4.6 and-16.3 dB,respectively,while the insertion loss and channel non-uniformity of the upstream power combiner can reach 3.5 and 2.1 dB,respectively.The proposed structure can readily be extended to other material platforms such as the silica-based planar lightwave circuit.Its fabrication process is fully compatible with standard clean-room technologies such as photolithography and etching,without any complicated and/or costly approach involved.展开更多
Augmented reality(AR)displays are emerging as the next generation of interactive platform,providing deeper humandigital interactions and immersive experiences beyond traditional flat-panel displays.Diffractive wavegui...Augmented reality(AR)displays are emerging as the next generation of interactive platform,providing deeper humandigital interactions and immersive experiences beyond traditional flat-panel displays.Diffractive waveguide is a promising optical combiner technology for AR owing to its potential for the slimmest geometry and lightest weight.However,severe chromatic aberration of diffractive coupler has constrained widespread adoption of diffractive waveguide.Wavelength-dependent light deflection,caused by dispersion in both in-coupling and out-coupling processes,results in limited full-color field of view(FOV)and nonuniform optical responses in color and angular domains.Here we introduce an innovative full-color AR system that overcomes this long-standing challenge of chromatic aberration using a combination of inverse-designed metasurface couplers and a high refractive index waveguide.The optimized metasurface couplers demonstrate true achromatic behavior across the maximum FOV supported by the waveguide(exceeding 45°).Our AR prototype based on the designed metasurface waveguide,exhibits superior color accuracy and uniformity.This unique achromatic metasurface waveguide technology is expected to advance the development of visually compelling experience in compact AR display systems.展开更多
Holographic near-eye augmented reality(AR)displays featuring tilted inbound/outbound angles on compact optical combiners hold significant potential yet often struggle to deliver satisfying image quality.This is primar...Holographic near-eye augmented reality(AR)displays featuring tilted inbound/outbound angles on compact optical combiners hold significant potential yet often struggle to deliver satisfying image quality.This is primarily attributed to two reasons:the lack of a robust off-axis-supported phase hologram generation algorithm;and the suboptimal performance of ill-tuned hardware parts such as imperfect holographic optical elements(HOEs).To address these issues,we incorporate a gradient descent-based phase retrieval algorithm with spectrum remapping,allowing for precise hologram generation with wave propagation between nonparallel planes.Further,we apply a camera-calibrated propagation scheme to iteratively optimize holograms,mitigating imperfections arising from the defects in the HOE fabrication process and other hardware parts,thereby significantly lifting the holographic image quality.We build an off-axis holographic near-eye display prototype using off-the-shelf light engine parts and a customized full-color HOE,demonstrating state-of-the-art virtual reality and AR display results.展开更多
We demonstrate a high-power blue diode laser operated at 447 nm combining laser diodes using an optical fiber bundle. As many as 127 diode lasers at 447 nm were coupled into 400 μm/0.22 NA fibers using an aspherical ...We demonstrate a high-power blue diode laser operated at 447 nm combining laser diodes using an optical fiber bundle. As many as 127 diode lasers at 447 nm were coupled into 400 μm/0.22 NA fibers using an aspherical lens group with different focus lengths. The bare fibers were mechanically bundled through high temperature ultraviolet adhesive after the coatings of the 127 fibers were stripped. The diameter of the fiber bundle was 6 mm. The total output power of such a bundle was 152 W with electro-optical conversion efficiency of 27.56%and the RMS power instability was less than ±1% within 3 h.展开更多
基金Project(52175445)supported by the National Natural Science Foundation of ChinaProject(2022JJ30743)supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(2023GK2024)supported by the Key Research and Development Program of Hunan Province,ChinaProject(2023ZZTS0391)supported by the Fundamental Research Funds for the Central Universities of China。
文摘Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extensive attention due to their advantages of small size,high multiplexing efficiency,convenient mass production,and low cost.An RGB beam combiner based on directional couplers is designed,with a core-cladding relative refractive index difference of 0.75%.The RGB beam combiner is optimized from the perspective of parameter optimization.Using the beam propagation method(BPM),the relationship between the performance of the RGB beam combiner and individual parameters is studied,achieving preliminary optimization of the device’s performance.The key parameters of the RGB beam combiner are optimized using the entropy weight-technique for order preference by similarity to an ideal solution TOPSIS method,establishing the optimal parameter scheme and further improving the device’s performance indicators.The results show that after optimization,the multiplexing efficiencies for red,green,and blue lights,as well as the average multiplexing efficiency,reached 99.17%,99.76%,96.63%and 98.52%,respectively.The size of the RGB beam combiner is 4.768 mm×0.062 mm.
基金The authors would like to acknowledge the financial support of NSERC Discovery Grants and the Canada Research Chair(CRC)Program
文摘Improved all-optical OR gates are proposed, using a novel fiber nonlinearity-based technique, based on the principles of combined Brillouin gain and loss in a polarization-maintaining fiber （PMF）. Switching contrasts are simulated to be between 82.4%-83.6%, for two respective configurations, and switching time is comparable to the phonon relaxation time in stimulated Brillouin scattering （SBS）.
文摘In this paper,we have proposed a hybrid optical wavelength demultiplexer and power combiner for a hybrid timeand wavelength-division multiplexing(TWDM)passive optical network(PON),i.e.,a single passive optical device that functions as a 1×N wavelength demultiplexer for distributing the downstream signal in multiple wavelengths from the optical line terminal(OLT)to the N optical network units(ONUs),and simultaneously as an N×1 power combiner for collecting the upstream signal in the same wavelength from the N ONUs to the OLT.Through a design example of a 32 channel hybrid optical wavelength demultiplexer and power combiner on the silicon-on-insulator platform,our numerical simulation result shows that the insertion loss and adjacent channel crosstalk of the downstream wavelength demultiplexer are as low as 4.6 and-16.3 dB,respectively,while the insertion loss and channel non-uniformity of the upstream power combiner can reach 3.5 and 2.1 dB,respectively.The proposed structure can readily be extended to other material platforms such as the silica-based planar lightwave circuit.Its fabrication process is fully compatible with standard clean-room technologies such as photolithography and etching,without any complicated and/or costly approach involved.
基金supported by the National Key Research and Development Program of China(No.2022YFB3602903)Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting(No.2017KSYS007)+2 种基金Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting(No.ZDSYS201707281632549)Shenzhen Science and Technology Program(No.JCYJ20220818100411025)Shenzhen Development and Reform Commission Project(Grant No.XMHT20220114005).
文摘Augmented reality(AR)displays are emerging as the next generation of interactive platform,providing deeper humandigital interactions and immersive experiences beyond traditional flat-panel displays.Diffractive waveguide is a promising optical combiner technology for AR owing to its potential for the slimmest geometry and lightest weight.However,severe chromatic aberration of diffractive coupler has constrained widespread adoption of diffractive waveguide.Wavelength-dependent light deflection,caused by dispersion in both in-coupling and out-coupling processes,results in limited full-color field of view(FOV)and nonuniform optical responses in color and angular domains.Here we introduce an innovative full-color AR system that overcomes this long-standing challenge of chromatic aberration using a combination of inverse-designed metasurface couplers and a high refractive index waveguide.The optimized metasurface couplers demonstrate true achromatic behavior across the maximum FOV supported by the waveguide(exceeding 45°).Our AR prototype based on the designed metasurface waveguide,exhibits superior color accuracy and uniformity.This unique achromatic metasurface waveguide technology is expected to advance the development of visually compelling experience in compact AR display systems.
基金National Key Research and Development Program of China(2021YFB2802200)National Natural Science Foundation of China(62322217,62005154)+1 种基金Natural Science Foundation of Shanghai Municipality(20ZR1420500)University Grants Committee(ECS27212822,GRF 17208023)。
文摘Holographic near-eye augmented reality(AR)displays featuring tilted inbound/outbound angles on compact optical combiners hold significant potential yet often struggle to deliver satisfying image quality.This is primarily attributed to two reasons:the lack of a robust off-axis-supported phase hologram generation algorithm;and the suboptimal performance of ill-tuned hardware parts such as imperfect holographic optical elements(HOEs).To address these issues,we incorporate a gradient descent-based phase retrieval algorithm with spectrum remapping,allowing for precise hologram generation with wave propagation between nonparallel planes.Further,we apply a camera-calibrated propagation scheme to iteratively optimize holograms,mitigating imperfections arising from the defects in the HOE fabrication process and other hardware parts,thereby significantly lifting the holographic image quality.We build an off-axis holographic near-eye display prototype using off-the-shelf light engine parts and a customized full-color HOE,demonstrating state-of-the-art virtual reality and AR display results.
基金Project supported by the Beijing Engineering Technology Research Center of All-Solid-State Lasers Advanced Manufacturing the National High Technology Research and Development Program of China(No.2014AA032607)+1 种基金the National Natural Science Foundation of China(Nos.61404135,61405186,61308032,61308033)the National Key R&D Program of China(Nos.2016YFB0401804,2016YFB0402002)
文摘We demonstrate a high-power blue diode laser operated at 447 nm combining laser diodes using an optical fiber bundle. As many as 127 diode lasers at 447 nm were coupled into 400 μm/0.22 NA fibers using an aspherical lens group with different focus lengths. The bare fibers were mechanically bundled through high temperature ultraviolet adhesive after the coatings of the 127 fibers were stripped. The diameter of the fiber bundle was 6 mm. The total output power of such a bundle was 152 W with electro-optical conversion efficiency of 27.56%and the RMS power instability was less than ±1% within 3 h.
