Low Refractive Index Research Articles

Revisiting the scattering regime map based on transport scattering coefficient for dielectric particulate medium

The independent scattering assumption is frequently employed in radiative transfer, as it is applicable to numerous scientific and practical scenarios involving sparsely distributed scatterers. However, dependent scattering effects must be considered if the particle distribution is not sparse, which requires a relatively more rigorous analysis. A scattering regime map that summarizes the conditions where the independent scattering assumption can be used safely was established in the 1980s. The validity of this regime map and corresponding transition criteria has been questioned due to revealed inaccuracies in certain portions of the map based on the recent experimental studies. This study aims to reevaluate the regime map for dielectric particulate medium through numerical simulations utilizing dense medium radiative transfer theory relying on static structure factor for incorporating the effects of dependent scattering. The transport scattering coefficient, encompassing both the scattering coefficient and the asymmetry parameter, is employed as the metric of evaluation as it accounts for both the quantitative and directional behavior of the scattering. Besides, it also reflects the behavior of reflectance/transmittance closely, which is presented by comparing the regime maps based on transport scattering coefficient and reflectance. While the resulting modified regime map agrees mostly with the established map, it corrects the parts where discrepancies were observed so that the modified map is in agreement with all available data. Moreover, the effects of particle size distribution and material properties are also investigated and it was found that a regime map for lower relative refractive index miss-match between particle and medium produces a demarcation line that is more conservative.

Optimizing the structural, thermal, gas sensing and electrical properties of in-situ polymerized poly(thiophene-co-indole)/silicon carbide nanocomposites for energy storage applications

Conducting copolymer nanocomposites of thiophene and indole incorporated with silicon carbide nanoparticles [poly (thiophene-co-indole-SiC) (PPSiC)] has been developed by in-situ copolymerization and these nanocomposites were characterized by different analytical techniques. The FTIR peak at 865 cm−1 signifies the successful incorporation of SiC nanoparticles in the copolymer matrix. The intensity of the UV-Vis absorbance of the copolymer nanocomposites increased with the nanoparticle concentrations, and PPSiC7 showed the highest intensity. This was in correlation with its low optical bandgap energy (3.032 eV) and high refractive index (2.388) value. XRD revealed the consistent positioning of sharp and distinct crystalline peaks of SiC in the copolymer. SEM revealed the effective dispersion of nanoparticles throughout the matrix and uniform dispersion was obtained for PPSiC7 nanocomposite. HR-TEM images validated the presence of spherical-shaped particles in the nanocomposite with the nano-size distribution of SiC. The surface roughness of the copolymer nanocomposite was evident from AFM analysis. TGA and DSC revealed that PPSiC nanocomposites have better thermal properties than the copolymer. AC conductivity increased with frequency and temperature. The PPSiC7 exhibits a maximum conductivity of 1.5×10−2 S/cm at 106 Hz and an activation energy of 0.064 eV. PPSiC nanocomposites demonstrated excellent results in degrading dye and detecting ammonia gas at ambient temperature. All analyses showed that the PPSiC7 nanocomposite exhibited superior properties than the copolymer. These admirable properties can be exploited in developing optoelectronic devices, energy storage devices and gas sensors.

Fano resonance-enhanced planar waveguide sensor utilizing MoS2 for high-performance sensing application

Sensing performance of a Fano resonance waveguide based sensor having a MoS2 material assisted with low refractive index coupling prism BK7 is analyzed. Position of MoS2 is optimized by considering two six-layer structural configurations i.e. PAMCFS and PMACFS and their results are compared at particular guiding layer thickness 500 nm and coupling layer thickness 700 nm. The reflectance formula of proposed six-layer waveguide is obtained using Fresnel’s equations. Our analysis shows that the PAMCFS waveguide gives better sensing performance than PMACFS. Further, sensing parameters is analyzed for different thickness of coupling layer and guiding layer. The maximum obtained sensitivity for zero order Fano resonance mode in intensity interrogation of the proposed PAMCFS waveguide structure is 6.847 × 106 a.u.-RIU–1 at guiding layer thickness 800 nm and coupling layer thickness 1000 nm. Also, at these thicknesses, FWHM is obtained in order of ∼10−6 while the achieved detection accuracy and figure of merit in order of ∼107 and ∼106 respectively.

Ultrasensitive Silicon Photonic Refractive Index Sensor Based on Hybrid Double Slot Subwavelength Grating Microring Resonator.

Silicon photonic-based refractive index sensors are of great value in the detection of gases, biological and chemical substances. Among them, microring resonators are the most promising due to their compact size and narrow Lorentzian-shaped spectrum. The electric field in a subwavelength grating waveguide (SWG) is essentially confined in the low-refractive index dielectric, favoring enhanced analyte-photon interactions, which represents higher sensitivity. However, it is very challenging to further significantly improve the sensitivity of SWG ring resonator refractive index sensors. Here, a hybrid waveguide blocks double slot subwavelength grating microring resonator (HDSSWG-MRR) refractive index sensor operating in a water refractive index environment is proposed. By designing a new waveguide structure, a sensitivity of up to 1005 nm/RIU has been achieved, which is 182 nm/RIU higher than the currently highest sensitivity silicon photonic micro ring refractive index sensor. Meanwhile, utilizing a unique waveguide structure, a Q of 22,429 was achieved and a low limit of detection of 6.86 × 10-5 RIU was calculated.

Wavelength multiplexing system based on ring resonators

Wavelength Division Multiplexing, WDM, is a technology developed for applications in telecommunications with the purpose of combining numerous wavelength signals into one single fibre. The aim of this research is the characterization of WDM systems of ring resonators with planar optical waveguides. The optical responses for different configurations, dimensions, and materials are analysed by doing a parametric study both considering analytical expressions and a Finite Element Tool. The results are from add-drop topologies with one, two and three rings. The main difference between topologies with the same parameters is the number of resonance wavelengths, which is higher due to the increase in the number of ring-shaped waveguides. It is concluded that adjusting the rings’ dimensions, the resonant wavelengths are tuned. Furthermore, the higher the rings’ radius the lower is the free spectral range, that can take values from 40 nm to 90 nm. Then, the number of resonant peaks in a wavelength range may change. Also, 1500–5000 describes the values computed for the quality factor, whereas the full width at half maximum varies within some units of nanometres. For models with different core materials, the higher transmittances decrease with lower core refractive indexes and the resonance width increases. These are new degrees of freedom to tune the response of the device that can definitely work as optical wavelength multiplexer, having losses from 20% to 40% considering the transmitted optical power.

Enhancing Light Outcoupling Efficiency via Anisotropic Low Refractive Index Electron Transporting Materials for Efficient Perovskite Light-Emitting Diodes.

Thanks to the extensive efforts toward optimizing perovskite crystallization properties, high-quality perovskite films with near-unity photoluminescence quantum yield are successfully achieved. However, the light outcoupling efficiency of perovskite light-emitting diodes (PeLEDs) is impeded by insufficient light extraction, which poses a challenge to the further advancement of PeLEDs. Here, an anisotropic multifunctional electron transporting material, 9,10-bis(4-(2-phenyl-1H-benzo[d]imidazole-1-yl)phenyl) anthracene (BPBiPA), with a low extraordinary refractive index (ne) and high electron mobility is developed for fabricating high-efficiency PeLEDs. The anisotropic molecular orientations of BPBiPA can result in a low ne of 1.59 along the z-axis direction. Optical simulations show that the low ne of BPBiPA can effectively mitigate the surface plasmon polariton loss and enhance the photon extraction efficiency in waveguide mode, thereby improving the light outcoupling efficiency of PeLEDs. In addition, the high electron mobility of BPBiPA can facilitate balanced carrier injection in PeLEDs. As a result, high-efficiency green PeLEDs with a record external quantum efficiency of 32.1% and a current efficiency of 111.7cd A-1 are obtained, which provides new inspirations for the design of electron transporting materials for high-performance PeLEDs.

Wavelength Scale Singlet Achromatic Microlenses Based on High Refractive Index Materials

AbstractThe common methods used for correcting chromatic aberration are typically based on multi‐lens and multi‐material systems, resulting in lens thicknesses that are several orders of magnitude greater than the wavelength and complex combination designs. A method to achieve the singlet achromatic microlens of the wavelength‐scale thickness by utilizing high refractive index materials with an aspherical profile is proposed. A theoretical model based on the dispersion effect is developed to guide the selection of materials and the design of thicknesses for achieving chromatic aberration correction in singlet microlenses of a given diameter and numerical aperture. H‐ZLaF68N (68N) glass, sapphire, and fused silica with relatively high to low refractive index are selected to prepare the singlet achromatic microlenses to verify the validity of the model. The thicknesses of three microlenses are 573, 737 nm, and 1.27 µm, respectively, and all of them have achieved achromatic correction as designed. This indicates that the high refractive index material not only achieves achromatic aberration but also reduces the thickness by ≈50% compared with the conventional low refractive index material of silica glass. The presented wavelength‐scale singlet achromatic microlens hold significant promise for compact wearable devices, dynamic holography, and color projection displays.

Preparation and properties of Si3N4 ceramics via vat photopolymerization using Si3N4 powders coated with bowl-like boehmite

It is a significant challenge to fabricate Si3N4 ceramics due to the high refractive index (2.1) and UV absorbance (0.8903 at the wavelength of 405 nm) of Si3N4 powders. In this study, a method of filling Si3N4 powders into bowl-like hollow boehmite microspheres was proposed. And the effects of the boehmite coating content on the properties of Si3N4 ceramic slurries, green bodies and sintered samples were systematically investigated. Due to its low refractive index (1.7) and weak UV absorbance (0.2648 at the wavelength of 405 nm), boehmite can serve as a modifier to enhance the photocuring ability of Si3N4 ceramic slurries. At the same time, it can also be decomposed into Al2O3 at high temperature as a sintering aid of Si3N4 ceramics. As the boehmite coating content increased from 2.5 wt% to 10 wt%, the bulk density of Si3N4 ceramic samples decreased from 3.05 ± 0.01 g/cm3 to 2.79 ± 0.03 g/cm3, while the porosity increased from 6.84 ± 0.81% to 13.23 ± 0.93%. The relative density (93.15 ± 0.02%) and flexural strength (406.5 ± 18.3 MPa) of sintered Si3N4 ceramic samples revealed that both values peaked at 2.5 wt%. This study not only provides a constructive method for modifying Si3N4 powders to achieve photopolymerization, but also offers an innovative idea for other non-oxidation ceramics with poor photocuring ability.

Calculations of the mechanical, optoelectronic, and magnetic properties of FrGeX3 (X = Cl, Br, I) under hydrostatic pressures based on first-principles theories

Using first-principles calculations based on density functional theory, this work investigated the mechanical, magnetic, elastic, electrical, and optical characteristics of the halide-based perovskite FrGeX3 (X = Cl, Br, I) at different hydrostatic pressures ranging from 0 to 9 GPa. It was determined that the compound FrGeX3 (X = Cl, Br, I) is stable and ductile in nature by calculating its thermodynamic and mechanical stability using the parameters of its formation enthalpy and elastic constant. When no hydrostatic pressure is applied, the band computations reveal that FrGeCl3, FrGeBr3, and FrGeI3 all remain in the semiconductor region with bandgaps of 1.14, 0.8, and 0.645 eV, respectively. The study examined how increasing induced pressure affects the bandgap and density of states of the structure for all three halides. The bandgap of FrGeCl3, FrGeBr3, and FrGeI3 fell to 0 eV at 9, 6, and 5 GPa, respectively. In addition, the optical absorption, reflectivity, refractive index, and imaginary and real components of dielectric functions were all studied in detail for cubic perovskites FrGeX3 (X = Cl, Br, I) under varying hydrostatic pressures, from 0 to 9 GPa. Due to increased pressure, the compound transitioned into a conductor and improved its absorption capabilities for all compounds within the 8–14 eV range, making it suitable for use in the UV spectrum. Cl has the largest absorption among all compounds, whereas I displays the lowest. Reflectivity ranges from around 14% to 18% for all compounds and increases w%ith pressure. The actual component of the refractive index ranges from around 2.25 to 2.7 at 0 eV and increases with pressure. Chlorine has a low refractive index, whereas iodine demonstrates the greatest. The highest fluctuation is shown for Br. The dielectric characteristics vary from around 5 to 7.5 F/m. Chlorine (Cl) has the least charge storage capacity, while iodine (I) demonstrates the most, of which both increase with pressure in all compounds. Structure FrGeX3 (X = Cl, Br, I) is hardened and made more ductile by applying hydrostatic pressure, as seen by the increasing bulk, Young’s, and shear modulus values, as well as the elastic constants (C11 and C12). While the electrons were in a co-linear position, the magnetic property was also studied by optimizing the band structure and density of states. The diamagnetic property of the combination FrGeX3 (where X = Cl, Br, I) remained unchanged even when subjected to increased pressure. According to the findings, this perovskite material has remarkable absorption properties, which point to a change in its behavior from semiconductor to metal. Their potential uses in solar cells, UV absorbers, and optoelectronic devices are highlighted by these computational results.

Structural control of corneal transparency, refractive power and dynamics.

The cornea needs to be transparent to visible light and precisely curved to provide the correct refractive power. Both properties are governed by its structure. Corneal transparency arises from constructive interference of visible light due to the relatively ordered arrangement of collagen fibrils in the corneal stroma. The arrangement is controlled by the negatively charged proteoglycans surrounding the fibrils. Small changes in fibril organisation can be tolerated but larger changes cause light scattering. Corneal keratocytes do not scatter light because their refractive index matches that of the surrounding matrix. When activated, however, they become fibroblasts that have a lower refractive index. Modelling shows that this change in refractive index significantly increases light scatter. At the microscopic level, the corneal stroma has a lamellar structure, the parallel collagen fibrils within each lamella making a large angle with those of adjacent lamellae. X-ray scattering has shown that the lamellae have preferred orientations in the human cornea: inferior-superior and nasal-temporal in the central cornea and circumferential at the limbus. The directions at the centre of the cornea may help withstand the pull of the extraocular muscles whereas the pseudo-circular arrangement at the limbus supports the change in curvature between the cornea and sclera. Elastic fibres are also present; in the limbus they contain fibrillin microfibrils surrounding an elastin core, whereas at the centre of the cornea, they exist as thin bundles of fibrillin-rich microfibrils. We present a model based on the structure described above that may explain how the cornea withstands repeated pressure changes due to the ocular pulse.

Er‐Doped MgAl2O4 Nanofilms Enabling Highly Efficient Near‐Infrared Electroluminescence from the Silicon‐Based MOS Devices Fabricated by Atomic Layer Deposition

AbstractEr3+‐doped polycrystalline MgAl2O4 (MAO:Er) spinel nanofilms are deposited via atomic layer deposition, and the metal‐oxide–semiconductor light emitting devices are fabricated. The crystallinity and morphology of the MAO:Er nanofilms are explored by modifying the annealing temperatures, Al2O3/MgO ratios and Er2O3 dopant cycles. The similar electroluminescence (EL) emissions peaking at 1530 nm indicates the identical crystal field environment for the doped Er3+ ions. The concentration quenching is verified to occurs via the energy transfer among the neighboring Er3+ ions. The optimal device (800 °C‐annealed, Al2O3/MgO ratio close to stoichiometry, Er3+: 1.85 mol%) yields the highest external quantum efficiency of 28%, the power efficiency of 0.32% and the optical power density of 14.62 mW cm−2. The smooth MAO:Er spinel nanofilms with the low refractive index and high resistance ensure the highly efficient light extraction and the generation of energetic electrons for the impact excitation of Er3+ ions. The trap‐assisted tunneling under operation electric field dominates the conduction mechanism for the EL emissions. The estimated decay lifetime of 1154.4 µs and a large‐stimulated emission cross‐section in the order of 10−15–10−14 cm2 are revealed from the EL emissions. Intense near‐infrared emissions from these Si‐based MAO:Er devices have great potential in the optoelectronic applications.

Multilayer dielectric reflector using low-index nanolattices.

Dielectric mirrors based on Bragg reflection and photonic crystals have broad application in controlling light reflection with low optical losses. One key parameter in the design of these optical multilayers is the refractive index contrast, which controls the reflector performance. This work reports the demonstration of a high-reflectivity multilayer photonic reflector that consists of alternating layers of TiO2 films and nanolattices with low refractive index. The use of nanolattices enables high-index contrast between the high- and low-index layers, allowing high reflectivity with fewer layers. The broadband reflectance of the nanolattice reflectors with one to three layers has been characterized with peak reflectance of 91.9% at 527 nm and agrees well with theoretical optical models. The high-index contrast induced by the nanolattice layer enables a normalize reflectance band of Δλ/λo of 43.6%, the broadest demonstrated to date. The proposed nanolattice reflectors can find applications in nanophotonics, radiative cooling, and thermal insulation.

Low-threshold AlGaN-based deep ultraviolet laser enabled by a nanoporous cladding layer.

We demonstrated an AlGaN-based multiple-quantum-well (MQW) deep ultraviolet (DUV) laser at 278 nm using a nanoporous (NP) n-AlGaN as the bottom cladding layer grown on the sapphire substrate. The laser has a very-low-threshold optically pumped power density of 79 kW/cm2 at room temperature and a transverse electric (TE)-polarization-dominant emission. The high optical confinement factor of 9.12% benefiting from the low refractive index of the nanoporous n-AlGaN is the key to enable a low-threshold lasing. The I-V electrical measurement demonstrates that an ohmic contact can be still achieved in the NP n-AlGaN with a larger but acceptable resistance, which indicates it is compatible with electrically driven laser devices. Our work provides insights into the design and fabrication of low-threshold lasers emitting in the DUV regime.

Terahertz Time-Domain Spectroscopic (THz-TDS) Insights into Protein Deformation

In this study, we utilized terahertz time-domain spectroscopy (THz-TDS) to study the radiation-induced protein deformation. The absorption coefficient spectra obtained from THz-TDS measurements in the frequency range (0.06–2 THz) was fitted using the Lorentzian model. The absorption coefficient fitting data was used to identify the α-helix and β-structure relative contributions in the protein secondary structure of the kidney tissue of rats irradiated with 10-cGy and 2-Gy X-ray separately or in combination. Our data show that 2-Gy X-irradiation leads to an increase in the β-structure contribution associated with a decrease in the α-helix contribution as indicated by the fitting parameters extracted from fitting the absorption coefficient α(ω) spectra with the Lorentzian function. The results point out that there is a strong correlation between the strength of the hydrogen bonds located between or inside the polypeptide chains of the extended β-sheet and α-helix, respectively, and the absolute value of the absorption coefficient α(ω), the refractive index, and the dielectric constant. The lowest refractive index and dielectric constant are recorded in the 2-Gy-irradiated group followed by the 10-cGy–2 Gy-irradiated group while the least effect was recorded in the 10-cGy-irradiated group. These data provide evidence of the adaptive effect of the 10-cGy X-irradiation delivered 24 h prior to the 2-Gy x-irradiation.

Design Study High Reflectors Graded Index Mirror Dispersive Properties

This paper investigates the dispersive properties of a spectral filter—a quarter-wave (QW) mirror. The study considers the modeling with a smoothly changing refractive index of the applied material (Rugate filter) using Fourier transform analysis of a high and low refractive index. These chirped structures exhibit high reflectivity and low group delay dispersion. The introduced result in this study is in some way better than already existing ones and/or can be used to obtain a meaningful practical effect, because it adopts calculation methods that are characterized by the accuracy and reliability of data using different statistical parameters and can be adopted with all modern and old methods of preparation. These improvements can have significant implications for various applications. Moreover, we investigate different statistical parameters, such as mean, median, mode, and standard deviation (STD), and analyze their impact on the rugate filter group delay (GD) and group delay dispersion (GDD) performance.

High-directivity far-field radiation of quantum dot-based single-photon emitter coupled to polymeric circular waveguide resonant grating

Solid-state single-photon emitters (SPEs) commonly encounter the limitation of quasi-omnidirectional radiation patterns, which poses challenges in utilizing their emission with conventional optical instruments. In this study, we demonstrate the tailoring of the far-field radiation patterns of SPEs based on colloidal quantum dots (QDs), both theoretically and experimentally, by employing a polymer-based dielectric antenna. We introduce a simple and cost-effective technique, namely low one-photon absorption direct laser writing, to achieve precise coupling of a QD into an all-polymer circular waveguide resonance grating. By optimizing the geometry parameters of the structure using 3D finite-difference time-domain simulations, resonance at the emission wavelength of QDs is achieved in the direction perpendicular to the substrate, resulting in photon streams with remarkably high directivity on both sides of the grating. Theoretical calculations predict beam divergence values below 2°, while experimental measurements using back focal plane imaging yield divergence angles of approximately 8°. Our study contributes to the evaluation of concentric circular grating structures employing low refractive index polymer materials, thereby expanding the possibilities for their application.

Traceable characterization of hollow organosilica beads as potential reference materials for extracellular vesicle measurements with optical techniques

The concentration of cell-type specific extracellular vesicles (EVs) is a promising biomarker for various diseases. However, concentrations of EVs measured by optical techniques such as flow cytometry (FCM) or particle tracking analysis (PTA) in clinical practice are incomparable. To allow reliable and comparable concentration measurements suitable reference materials (RMs) and SI-traceable (SI—International system of units) methods are required. Hollow organosilica beads (HOBs) are promising RM candidates for concentration measurements of EVs based on light scattering, as the shape, low refractive index, and number concentration of HOBs are comparable to EVs of the respective size range that can be detected with current optical instrumentation. Here, we present traceable methods for measuring the particle size distribution of four HOB types in the size range between 200 and 500 nm by small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM), as well as the number concentration by single-particle inductively coupled plasma mass spectrometry (spICP-MS). Based on the size and shape results, traceable reference values were obtained to additionally determine the refractive index of the shell of the HOB samples by FCM. Furthermore, the estimated refractive indexes of the HOBs plausibly agree with the refractive indexes of EVs of corresponding size. Due to their narrow size distribution and their similar shape, and low refractive index, all HOB samples studied are suitable RM candidates for calibration of the measured sample volume by optical methods within the photon wavelength range used, and thus for calibration of number concentration measurements of EVs in the size range indicated. This was confirmed as the number concentration values obtained by PTA and two independent flow cytometric measurements agreed with the concentration reference values obtained by two independent spICP-MS measurements within the calculated uncertainty limits.

D-type photonic crystal fiber low refractive index sensor based on surface plasmon

This study presents the design and analysis of a novel surface plasmon resonance sensor based on D-type photonic crystal fiber. The analyte channel in the sensor comprises an open ring with a thin gold film deposited on the channel, inducing the surface plasmon resonance effect to enhance the resonance effect and improve the spectral sensitivity of the sensor. The proposed design eliminates the need to introduce liquid into the analyte channel. Upon inserting the sensor into the vessel, the analyte automatically flows into the liquid channel. Simulations illustrate the capability of the proposed sensor to detect low refractive indices spanning from [Formula: see text] to [Formula: see text], exhibiting a remarkable spectral sensitivity of up to 9000[Formula: see text]nm/RIU. The surface plasmon resonance sensor presented in this study emerges as a competitive candidate for applications requiring low refractive index detection. It is all because of its promising sensing results, wide refractive index sensing range, and simple, compact fiber design.

Cascaded plastic optical fiber based SPR sensor for simultaneous measurement of refractive index and temperature.

A cascaded side-polish plastic optical fiber (POF) and FONTEX optical fiber based surface plasmon resonance (SPR) sensor is proposed for simultaneous measurement of refractive index (RI) and temperature. The side-polish POF and FONTEX optical fiber are connected by using the UV glue in a Teflon plastic tube. The SPR phenomenon can be excited at both of the side-polish region and the FONTEX fiber cladding. The polydimethylsiloxane (PDMS) is coated on the side-polish POF to get a temperature sensing channel. Due to the low RI sensitivity of the FONTEX optical fiber, the cascaded fiber sensor can obtain a broader RI measurement range with a low crosstalk. An RI sensitivity of 700 nm/RIU in the RI measurement range of 1.335-1.39 and a temperature sensitivity of -1.02 nm/°C measured in deionized water with a range of 20-60 °C are obtained. In addition, the cascaded POF based SPR sensor has potential application prospects in the field of biochemical sensing.

High-efficiency edge-emitting laser diodes with oxidation confinement stripe structure

High-efficiency, low-cost, high-power laser diodes (LDs) are in the spotlight due to the growing market demand. This study proposes a new edge-emitting LD structure that utilizes the facile oxidization properties of the high aluminum (Al) component AlGaAs material and simplifies LD fabrication to only one-step lithography. The key innovation is incorporating a ∼200 nm thick high-Al AlGaAs layer in the vertical epitaxial structure. This layer serves two purposes: 1) The low refractive index improves vertical mode confinement, enabling a thinner overall epitaxial structure. 2) Oxidation of this layer forms a dielectric isolator and a current aperture. Experimental LDs exhibited a peak efficiency of 77.8 %, peak power of 33.6 W, vertical divergence angle of 19.4°, and horizontal divergence angle of 8.8°. Compared to conventional edge-emitting LD, this LD demonstrates a 39 % lower thermal resistance, better optoelectronic performance, a simpler process, and a lower production cost.