Deep-ultraviolet (DUV) light is essential for applications including fabrication, molecular research, and biomedical imaging. Compact metalenses have the potential to drive further innovation in these fields, provided they utilize a material platform that cost-effective, durable, scalable. In this work, we present aluminum nitride (AlN) as an efficient solution DUV applications. These metalenses, with thickness of only 380 nm, deliver focusing imaging capabilities close theoretical...

We report indium incorporation properties on various nonpolar and semipolar free-standing GaN substrates. Electroluminescence characterization x-ray diffraction (XRD) analysis indicate that the (202¯1¯) (112¯2) planes have highest rate among studied planes. also show both composition polarization-related electric fields impact emission wavelength of quantum wells (QWs). The different magnitudes directions for each orientation result in potential profiles QWs, leading to wavelengths at a...

An advanced light-fidelity (Li-Fi) system based on the blue Gallium nitride (GaN) laser diode (LD) with a compact white-light phosphorous diffuser is demonstrated for fusing indoor white-lighting and visible light communication (VLC). The adhered GaN LD broadens luminescent spectrum diverges beam spot to provide ample functionality including completeness of Li-Fi feature quality white-lighting. diverged covers radiant angle up 120(o) CIE coordinates (0.34, 0.37). On other hand, degradation...

The lack of intrinsic mirror symmetry in cavity mirrors poses a significant challenge for most organic chiral materials generating circularly polarized (CP) lasers. However, nonreciprocal chiroptical materials, such as recently developed thin films exhibiting apparent circular dichroism (ACD), provide promising approach to CP light generation. In this work, we integrate an ACD-based film into free-space dye laser cavity, achieving direct emission with degree polarization (DOCP) up 0.6,...

A study of the influence embedded circular hollow vascules on structural performance a fibre-reinforced polymer (FRP) composite laminate is presented. Incorporating such will lead to multi-functional composites by bestowing functions as self-healing and active thermal management. However, presence off-axis leads localized disruption fibre architecture, i.e. resin-rich pockets, which are regarded internal defects may cause stress concentrations within structure. Engineering approaches for...

The optical polarization ratio of spontaneous emission was investigated by electroluminescence measurements for semipolar (202¯1¯) InGaN/GaN light-emitting diodes, covering the blue to green spectral range. Devices fabricated on substrates exhibit ratios ranging from 0.46 at 418 nm 0.67 519 nm. These are significantly higher than those reported (202¯1) devices. valence band energy separation is extracted and consistent with increased theoretical predictions. Quantum well interdiffusion...

We demonstrate electrically driven InGaN based laser diodes (LDs), with a simple AlGaN-cladding-free epitaxial structure, grown on semipolar (2021) GaN substrates. The devices employed In0.06Ga0.94N waveguiding layers to provide transverse optical mode confinement. A maximum lasing wavelength of 506.4 nm was observed under pulsed operation, which is the longest reported for III-nitride LDs. threshold current density (Jth) index-guided LDs uncoated etched facets 23 kA/cm2, and 19 kA/cm2 after...

Two-dimensional optical waveguide mode simulations have been employed to investigate the optimized device structures for ridge-waveguide (Al, In, Ga) N-based green (520nm) laser diodes (LDs). The effects of thicknesses, alloy compositions, and doping densities each epitaxially grown layers as well ridge geometries on confinement factors (Γ) absorption (α) were comprehensively surveyed. InyGa1−yN (y=0.07–0.1) guiding (GLs) with thickness more than 50nm effective realizing high Γ low α. To...

The growth of InGaN/AlGaN multiple quantum wells (MQWs) structures is highly effective for realizing high quality semipolar (2021) active regions green light emitting diodes (LEDs) and laser (LDs). use AlGaN barriers significantly improved internal efficiencies the uniformity emission compared to InGaN or GaN barriers. 516 nm lasing wavelength was demonstrated on substrates by introducing three periods MQWs AlGaN-cladding-free optical waveguide consisting cladding guiding layers.

Nonpolar blue-green (481 nm) InGaN/GaN laser diodes (LDs) were realized by using m-plane GaN substrates with a misorientation angle of approximately 1° toward [0001] direction. The diode structures grown on miscut showed significantly smoother surface morphology compared to nominally on-axis substrates. It is contributed lower threshold current densities, longer lasing wavelength, and higher yield than those the same growth condition. Material improvement based control substrate essential...

We investigate the influence of polarity on carrier transport in single-quantum-well and multiple-quantum-well (MQW) light-emitting diodes (LEDs) grown semipolar (202¯1) (2021¯) orientations free-standing GaN. For MQW LEDs with opposite to conventional Ga-polar c-plane LEDs, polarization-related electric field QWs results an additional energy barrier for carriers escape QWs. show that same have a more uniform distribution lower forward voltage than LEDs.

A high-quality and highly-transparent AlN template was prepared by regrowth on a sputter-deposited buffer layer. The layer thermally annealed then underwent in metalorganic chemical vapor deposition (MOCVD). peakwidth of (002) (102) plane x-ray rocking curve 104 arcsec 290 arcsec, respectively, indicating threading dislocation density <5.0 × 108 cm−2. Dislocations were reduced via grain growth morphological evolution. absence carbon impurity source sputter also resulted an improved...

We demonstrate intersuband InGaN/(Al)GaN quantum well infrared photodetectors grown on a free standing non-polar m-plane GaN substrate. The devices are by metal organic chemical vapor deposition and exhibit TM-polarized photocurrent at peak wavelengths of 7.5 9.3 μm temperature 14 K. Based the experimental data intersubband interband transition energies 8-band k · p Schrödinger-Poisson solver calculations, we were able to estimate conduction band offset valence discontinuity ratio (ΔEc:ΔEv)...

We have demonstrated AlGaN-cladding-free m-plane InGaN-based blue laser diodes (LDs) using a novel structure that employs 50-nm-thick n- and p-type InxGa1-xN (x = 5–10%) as waveguiding layers. The thick, high In content InGaN layers provided significant refractive index contrast to the GaN cladding layers, thereby eliminating need for AlGaN cladding. Under pulsed operation, lasing was achieved at 442 nm with threshold current density of 10 kA/cm2.

We demonstrate GaN-based semipolar (2021¯) laser diodes (LD) in the green region of spectrum. 505 nm lasing was observed under pulsed operation, with a threshold current density (Jth) 27.5 kA/cm2 and voltage (Vth) 15.5 V. The blueshift spontaneous emission less than 5 when varying injection level from 125 A/cm2 to threshold. Simulations show that reduced can be attributed minimal dependence energy potential profile active on applied bias level.

We designed and fabricated the first bifocal meta-lens with a high-quality AlN buffer on sapphire substrate. According to ellipsometry measurement, refractive index of is above 2.2, extinction coefficient below 0.002 in whole ultraviolet (UV) spectral region. The meta-atom library consists nanofins near-unity half-wavelength plate efficiency full 2π coverage effective propagation phase converted spin. Two independent lens profiles for right-circularly polarized (RCP) left-circularly (LCP)...

The lack of intrinsic mirror symmetry in cavity mirrors poses a significant challenge for most organic chiral materials generating circularly polarized (CP) lasers. How ever, nonreciprocal chiroptical materials, such as the recently developed thin films exhibiting Apparent Circular Dichroism (ACD), provide promising approach to CPlight generation. In this work, we integrate an ACD-based film into free-space dye laser cavity, achieving direct CP emission with degree circular polarization...

We have demonstrated the InGaN/GaN single-quantum-well (SQW) red light-emitting diodes (LEDs) grown on free-standing GaN (202̄1) substrate with a forward voltage as low 2.8 V at 20 mA. A p-GaN growth temperature is required to prevent structure deterioration during growth. The reduction of was observed emission wavelength increased in SQW LEDs, which attributed its reversed polarization-related electric field compared conventional c -plane LEDs.

We report on void defect formation in (202¯1¯) semipolar InGaN quantum wells (QWs) emitting the green spectral region. Fluorescence and transmission electron microscopy studies indicate that this type of is associated with voids {101¯1}, {101¯0}, {0001¯} side facets QW Systematic growth show can be effectively suppressed by reducing rate for active Green light-emitting diodes (LEDs) reduced region showed enhanced power wavelength performance. The improved LED performance attributed to absence defects

The influence of compressive strain in high-quality AlN templates on the subsequent growth AlGaN-based device layers was investigated. showed ∼−0.29% and threading dislocation densities (TDDs) below 6.5 × 108 cm−2. By introducing high Si-doping MOVPE-grown AlN, relaxed while preserving low TDD. this method, TDD transferred from template to micron-thick n-Al0.63Ga0.37N. A 275 nm LED demonstrated with a ∼2.5 times power enhancement than same conventional under current injection. maximum...

Dark triangle defects (DTDs) are common nonradiative in semipolar <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(20\bar{2}1)$</tex></formula> oriented green quantum wells (QWs), commonly used laser diodes (LDs). We show that DTDs do not appear "as-grown," and DTD size depends strongly on post-QW-growth annealing time temperature. Using low temperature p-GaN, we prevent catastrophic QW damage...

We report the effects of Mg doping in barriers semipolar (202¯1) multiple-quantum-well light-emitting diodes (LEDs) with long emission wavelengths (&amp;gt;500 nm). With moderate concentrations (3 × 1018–5 1018 cm−3) barriers, output power was enhanced compared to those undoped which suggests that hole transport active region is a limiting factor for device performance. Improved injection due demonstrated by dichromatic LED experiments and band diagram simulations. Mg-doped AlGaN...