GaN-based devices have grown rapidly in recent decades, due to their important research value and application prospects. There is a desire monolithically integrate different GaN into single chip for the development of future optoelectronic systems with low power consumption. In addition improved multifunctional performance, miniature integrated system can result significant reduction material costs, processing packaging costs. view such prospects, we propose monolithic, top-down approaches...

Exploring the spin transport characteristics of magnetic tunnel junctions based on half-metallic Heusler holds significance, not only in unraveling fundamental physics at play but also advancing applications spintronic devices. Here, density functional theory conjunction with non-equilibrium Green’s functions has been systematically employed to investigate two prominent alloys, Co2CrAl and CoFeCrAl, which are direct interest candidates junction. The electronic structures Hesler alloys reveal...

In this paper, systematical study on the focal shift phenomenon in planar lenses based GaN high contrast gratings was performed using finite element method (FEM). Influence of parameters including device size, designed length, total phase difference focusing performance is presented. It shows that mainly determined by Fresnel number lens, which nearly equal to divided π. The influence lens size and length can be attributed change number. Theoretical analysis diffraction theory employed...

The grating interferometer in the Littrow configuration uses quarter wave plates (QWPs) to modulate polarization measurement system determine autocollimation optical path. Fabrication errors and mounting of QWPs lead phase changes that generate errors. As an alternative, we propose a produces conical diffraction. Using instead beam's bypasses this source error. A 45 mm range experiment was performed yielded repeated error 40 nm. Experiments show has simple structure good repeatability is...

We fabricate a multilayer Fabry-Perot filter (FPF) on GaN-on-silicon platform. Being significantly different from conventional thin film FPFs formed smooth flat surfaces, this FPF is deposited in micropit, and takes suspended GaN membrane as its carrier, which makes the whole structure ultracompact. The reflection spectra of are characterized by using an angle-resolved microreflection measurement system. experimental results show that generally have considerable blue shift comparison with...

A reconstruction design method for an aspherical recording system varied line-space gratings is introduced. This converts the from achieving specific groove distribution coefficients within expansion model into of auxiliary mirror surface via ray-tracing method. The effects higher-order terms in are investigated and more accurate grating structure achieved. By varying target, this can be used to structures with any shapes.

To completely clarify the spectral responses of linear grating filters (LGFs) under full-conical incidence (where incident plane is parallel to bars), a bandstop LGF implemented on an HfO2-on-silicon platform, and its are comprehensively investigated. The measured spectra agree well with simulated outcomes. For TM- (or TE-) polarized wave incidence, there exists pair resonance bands, whose features differ significantly from each other. One band has high angular tolerance capable...

A subwavelength metal grating for generating azimuthally polarized beams was designed. The material determined by calculating the total thermal conductivity coefficient. modified particle swarm optimization (PSO), which has a two-step algorithm structure, and position-determined inertia weight performed to establish grating's structural parameters. Results show that an Au-Ti-Cu all-metal structure provides good conductivity. high duty cycle gives polarization selectivity of approximately...

In this paper, we demonstrate a method of utilizing UV erosion to regulate the diffraction efficiency polarization volume grating (PVG). This approach enables facile patterned control PVG while ensuring integrity element. Upon short‐duration erosion, noticeable decrease in is observed. Following prolonged exposure central wavelength exhibits red shift, accompanied by an extension bandwidth response.

This paper introduces an AR‐HUD system based on a polarization volume grating (PVG) waveguide. The PVG waveguide is optimized to achieve uniform exit pupil. To verify its performance, display was constructed. achieves 10×5°field of view at pupil distance 300mm, boasting light efficiency 5.02% and contrast ratio 21:1.

We report the design and implementation of a one-dimensional guided-mode resonance filter (1D-GMRF) aiming to achieve polarization insensitivity at conical mounting. (The incident plane is aligned neither perpendicularly nor parallelly grating bars.) The guideline indicates that, mounting, 1D-GMRF can be achieved by optimizing parameters excite fundamental TE TM waveguide modes simultaneously. Moreover, it revealed polarization-insensitive GMR position in angle-resolved spectra azimuthal...

Optimization of non-planar antireflective coating and back- (or front-) surface texturing are widely studied to further reduce the reflection losses increase sunlight absorption path in solar cells. Back reflectors have been developed from perfect mirror textured order light path, which can significantly improve efficiency allow for much thinner devices. A Lambertian surface, has most random texture, theoretically raise 4n2 times that a smooth surface. It's challenge however fabricate ideal...

Here, and in an attempt to identify a better alternative the conventional dual layer ARCs for III-V multi-junction concentrator cells operating with or without protective cover glass conjunction wide acceptance angles, we have undertaken systematic analysis of design parameters angular dependent antireflective properties dielectric grating formed, through implementation sub-wavelength arrays 2D pyramidal gratings ZnS TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...

In this paper, we design and theoretically investigate an ultracompact Fabry-Pérot filter (FPF) consisting of two silicon-based high-contrast gratings (HCGs). The is proposed for implemention on a double silicon-on-insulator (double-SOI) platform. By using the rigorous coupled wave analysis method, examine discuss influences various factors transmission properties filter. location peak capable being tuned efficiently by changing grating period, thickness, duty cycle, or cavity length. An...

This paper presents design of a multichannel spectrophotometer, which uses holographic concave grating as dispersive element. The flat spectral field the generates integration collimation, disperse and convergence. Meanwhile, CCD with 2048 pixels is placed on plane photodetectors so that system can eliminate mechanical scanning. Due to features those elements procedure, spectrophotometer shows more advantages structure new typed spectrometer becomes smaller, its stability, reproducibility...

Optimization of non-planar antireflective coating and back- (or front-) surface texturing are widely studied as advanced light management approach to further reduce the reflection losses increase sunlight absorption path in solar cells. Rear reflectors have been developed from coherent mirrors incoherent order path, which can significantly improve efficiency allow for much thinner devices. A Lambertian surface, has most random texture, theoretically raise 4n² times that a smooth...

In this letter, we demonstrated an all-fiber laser that can simultaneously radiate dual-color vortex beams by incorporating a dual-channel mode-selective coupler (DC-MSC) into the cavity. By optimizing phase-matching condition between LP01 and LP11 modes, wavelength-dependent mode coupling could be observed. case, broadband conversion with two isolated bands achieved, which totally covers gain of ytterbium erbium ion, enabling simultaneous generation (VBs) at <inline-formula...

In high X III-V concentrator applications sunlight is focused onto the surface of cell with a wide angular distribution that limits effectiveness conventional thin-film AR coatings. Furthermore transmission properties are generally degraded non-uniformly over electromagnetic spectrum which in case multi-junction solar cells leads to additional sub-cell current matching related losses. Here, and an attempt identify better alternative dual layer ARCs, we have undertaken systematic analysis...