Pub Date : 2025-07-24DOI: 10.1109/JQE.2025.3587557
{"title":"Theory of the Linewidth of Semiconductor Lasers","authors":"","doi":"10.1109/JQE.2025.3587557","DOIUrl":"https://doi.org/10.1109/JQE.2025.3587557","url":null,"abstract":"","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"61 3","pages":"1-6"},"PeriodicalIF":2.2,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-23DOI: 10.1109/JQE.2025.3591762
Jonathan Schuster;Daniel B. Habersat;Franklin L. Nouketcha;Brenda L. VanMil;Jeremy L. Smith;Gregory A. Garrett;Michael A. Derenge;Tilak Hewagama;Shahid Aslam;Dina M. Bower;Anand V. Sampath;Michael Wraback
Near-ultraviolet (NUV) Geiger-mode avalanche photodiodes (NUV-GM-APD) require high unity-gain quantum efficiency (QE), while operating above avalanche breakdown. 4H-SiC has long been established as a proven GM-APD in the UV-C (<280> $lt 3~mu $ m thick) to a separate-absorption charge-multiplication (SACM) architecture. However, using a SACM architecture to improve the NUV unity-gain QE has unique challenges: including deviating from existing front-side absorber SACM architectures to a very thick backside one. This is further compounded when binary semiconductor materials are used (e.g., 4H-SiC) instead of alloyed heterostructures (e.g., InGaP or HgCdTe), removing what is arguably the most versatile design parameter, the mole fraction of the alloy. To overcome these challenges, we have implemented a numerical model with a calibrated 4H-SiC material library for the development of APDs and leveraged it to design NUV-enhanced SACM structures, where both non-reach-through (NRT) and reach-through (RT) architectures have been considered. For the NRT-SACM case, it was determined that the doping profiles must be engineered such that two competing mechanisms are balanced: maximizing the minority carrier diffusion length in the absorber layer (AL, longest at lower AL doping), while minimizing the corresponding potential barrier at the AL/charge layer (CL) interface (lowest at higher AL doping). Conversely, in a RT-SACM architecture, it was determined that a narrow range of total charge in the CL properly modulated the electric field to be non-zero in the AL and sufficiently large in the multiplication layer (ML) to operate above avalanche breakdown. As such, it was determined that the CL design is exceptionally intolerant to variations in either layer thickness or doping. Leveraging design rules learned and reported in this paper, we have designed both types of SACM architectures: NRT-SACM APDs and RT-SACM APDs, with unity gain QE at 340 nm up to 32% and 71% respectively, while maintaining a large electric field in the ML required for Geiger-mode operation.
{"title":"Design Challenges in Binary 4H-SiC NUV-Enhanced SACM APDs","authors":"Jonathan Schuster;Daniel B. Habersat;Franklin L. Nouketcha;Brenda L. VanMil;Jeremy L. Smith;Gregory A. Garrett;Michael A. Derenge;Tilak Hewagama;Shahid Aslam;Dina M. Bower;Anand V. Sampath;Michael Wraback","doi":"10.1109/JQE.2025.3591762","DOIUrl":"https://doi.org/10.1109/JQE.2025.3591762","url":null,"abstract":"Near-ultraviolet (NUV) Geiger-mode avalanche photodiodes (NUV-GM-APD) require high unity-gain quantum efficiency (QE), while operating above avalanche breakdown. 4H-SiC has long been established as a proven GM-APD in the UV-C (<280> <tex-math>$lt 3~mu $ </tex-math></inline-formula>m thick) to a separate-absorption charge-multiplication (SACM) architecture. However, using a SACM architecture to improve the NUV unity-gain QE has unique challenges: including deviating from existing front-side absorber SACM architectures to a very thick backside one. This is further compounded when binary semiconductor materials are used (e.g., 4H-SiC) instead of alloyed heterostructures (e.g., InGaP or HgCdTe), removing what is arguably the most versatile design parameter, the mole fraction of the alloy. To overcome these challenges, we have implemented a numerical model with a calibrated 4H-SiC material library for the development of APDs and leveraged it to design NUV-enhanced SACM structures, where both non-reach-through (NRT) and reach-through (RT) architectures have been considered. For the NRT-SACM case, it was determined that the doping profiles must be engineered such that two competing mechanisms are balanced: maximizing the minority carrier diffusion length in the absorber layer (AL, longest at lower AL doping), while minimizing the corresponding potential barrier at the AL/charge layer (CL) interface (lowest at higher AL doping). Conversely, in a RT-SACM architecture, it was determined that a narrow range of total charge in the CL properly modulated the electric field to be non-zero in the AL and sufficiently large in the multiplication layer (ML) to operate above avalanche breakdown. As such, it was determined that the CL design is exceptionally intolerant to variations in either layer thickness or doping. Leveraging design rules learned and reported in this paper, we have designed both types of SACM architectures: NRT-SACM APDs and RT-SACM APDs, with unity gain QE at 340 nm up to 32% and 71% respectively, while maintaining a large electric field in the ML required for Geiger-mode operation.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"61 5","pages":"1-11"},"PeriodicalIF":2.1,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145090036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-21DOI: 10.1109/JQE.2025.3591043
Miaoxia Yan;Jing Li;Qi Qu;Weichen Zhao;Li Pei;Tigang Ning
A high-precision triangular waveform with tunable symmetry photonic generation scheme based on in-phase/quadrature-phase modulation and image-reject down conversion is proposed and analyzed. The optical carrier from the laser diode is split into two paths: one is injected into the I/Q modulator driven by a sinusoidal signal, while the other is injected into a frequency shifter to introduce a frequency offset. Different channels have different frequency offsets. The modulated and frequency-shifted signals enter the image-reject mixer to realize optical down conversion and suppress the frequency mixing interference in the frequency conversion process. Finally, the signals from both channels are coupled to synthesize the first to sixth-order harmonic fitting in the Fourier series. High-precision triangular waveforms generation with tunable symmetry coefficients and repetition frequency of 5 GHz are obtained by simulation. In order to verify the mechanism, a proof-of-concept experiment is carried out. This scheme effectively expands the multi-channel spectrum and enables high-precision functional waveform fitting.
{"title":"High-Precision Triangular Waveform With Tunable Symmetry Photonic Generation Based on Image-Reject Down Conversion","authors":"Miaoxia Yan;Jing Li;Qi Qu;Weichen Zhao;Li Pei;Tigang Ning","doi":"10.1109/JQE.2025.3591043","DOIUrl":"https://doi.org/10.1109/JQE.2025.3591043","url":null,"abstract":"A high-precision triangular waveform with tunable symmetry photonic generation scheme based on in-phase/quadrature-phase modulation and image-reject down conversion is proposed and analyzed. The optical carrier from the laser diode is split into two paths: one is injected into the I/Q modulator driven by a sinusoidal signal, while the other is injected into a frequency shifter to introduce a frequency offset. Different channels have different frequency offsets. The modulated and frequency-shifted signals enter the image-reject mixer to realize optical down conversion and suppress the frequency mixing interference in the frequency conversion process. Finally, the signals from both channels are coupled to synthesize the first to sixth-order harmonic fitting in the Fourier series. High-precision triangular waveforms generation with tunable symmetry coefficients and repetition frequency of 5 GHz are obtained by simulation. In order to verify the mechanism, a proof-of-concept experiment is carried out. This scheme effectively expands the multi-channel spectrum and enables high-precision functional waveform fitting.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"61 4","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144831865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-14DOI: 10.1109/JQE.2025.3588833
Su Ik Park;Oh Kee Kwon;Chul Wook Lee;Dong-Soo Shin;Jong-In Shim
To evaluate the effect of thermally isolated waveguide structure in a heater-based tunable distributed Bragg reflector (DBR) laser, the temperature distribution and thermo-optical characteristics are investigated at various heater powers. The reflection spectrum of the DBR is designed, and the tuning characteristics of the fabricated DBR laser are compared with simulation results. It is found that the waveguide temperature increases linearly with the heater power, whereas the effective refractive index increases nonlinearly, resulting in the corresponding nonlinear wavelength-tuning characteristics. In order to obtain efficient thermal tuning characteristics, a thermal isolation structure of the reverse-mesa waveguide is introduced. In this device, the temperature of the waveguide core increases steeply at low tuning power levels, resulting in highly efficient wavelength tuning properties. On the other hand, at high tuning power, the DBR reflection spectrum broadens and the side-mode suppression ratio (SMSR) performances degrades. These effects are found to be caused mainly by non-uniform temperature distribution along the longitudinal direction.
{"title":"Heater-Tuned Single-Grating Distributed Bragg Reflector Lasers With a Thermal Confinement Waveguide Structure","authors":"Su Ik Park;Oh Kee Kwon;Chul Wook Lee;Dong-Soo Shin;Jong-In Shim","doi":"10.1109/JQE.2025.3588833","DOIUrl":"https://doi.org/10.1109/JQE.2025.3588833","url":null,"abstract":"To evaluate the effect of thermally isolated waveguide structure in a heater-based tunable distributed Bragg reflector (DBR) laser, the temperature distribution and thermo-optical characteristics are investigated at various heater powers. The reflection spectrum of the DBR is designed, and the tuning characteristics of the fabricated DBR laser are compared with simulation results. It is found that the waveguide temperature increases linearly with the heater power, whereas the effective refractive index increases nonlinearly, resulting in the corresponding nonlinear wavelength-tuning characteristics. In order to obtain efficient thermal tuning characteristics, a thermal isolation structure of the reverse-mesa waveguide is introduced. In this device, the temperature of the waveguide core increases steeply at low tuning power levels, resulting in highly efficient wavelength tuning properties. On the other hand, at high tuning power, the DBR reflection spectrum broadens and the side-mode suppression ratio (SMSR) performances degrades. These effects are found to be caused mainly by non-uniform temperature distribution along the longitudinal direction.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"61 5","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144989999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The optoelectronic mixer is a critical component in millimeter-wave (MMW) and terahertz (THz) systems, facilitating the integration between optical fiber and wireless communication technologies. This study elucidates the optoelectronic mixing principles of the uni-traveling carrier photodiode (UTC-PD) and design a structure with high modulation bandwidth and low conversion loss. The designed mixer achieves a modulation bandwidth of 28.1 GHz with a conversion loss of 9.5 dB at a local oscillator (LO) signal frequency of 60 GHz. At LO signal frequency of 100 GHz, the modulation bandwidth decreases to 26.8 GHz, with a corresponding conversion loss of 16.4 dB.
{"title":"High-Modulation Bandwidth and Low-Conversion Loss UTC-PD Optoelectronic Mixer","authors":"Jihong Ye;Yongqing Huang;Mingxi Yang;Shuhu Tan;Xuejie Wang;Xiaomin Ren","doi":"10.1109/JQE.2025.3587600","DOIUrl":"https://doi.org/10.1109/JQE.2025.3587600","url":null,"abstract":"The optoelectronic mixer is a critical component in millimeter-wave (MMW) and terahertz (THz) systems, facilitating the integration between optical fiber and wireless communication technologies. This study elucidates the optoelectronic mixing principles of the uni-traveling carrier photodiode (UTC-PD) and design a structure with high modulation bandwidth and low conversion loss. The designed mixer achieves a modulation bandwidth of 28.1 GHz with a conversion loss of 9.5 dB at a local oscillator (LO) signal frequency of 60 GHz. At LO signal frequency of 100 GHz, the modulation bandwidth decreases to 26.8 GHz, with a corresponding conversion loss of 16.4 dB.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"61 5","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144990024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-04DOI: 10.1109/JQE.2025.3586201
David A. Montealegre;Weitao Dai;Matthew Z. Bellus;Logan M. Nichols;John P. Prineas
Mid-infrared (3–$5~mu $ m) LEDs have assumed greater importance optical gas sensors and have been explored for use in midinfrared LED arrays, in both cases to replace thermal pixels. Compared to thermal pixels, mid-infrared LEDs have near instantaneous settling times, achieve higher radiance, can have multi-spectral output, and are safer. Multispectral output creates the possibility of emission into narrowed bands for either sensing multiple gas species or creating dual emission thermal pixel arrays. However, their adoption for these applications is hindered by spectral crosstalk from emission tails at room temperature, and additionally by low efficiency, problematic in dense LED arrays with strict power density requirements. This work explores three approaches to designing two-color mid-infrared LED arrays, targeting reduced spectral crosstalk and lower power requirements: 1) monolithic two-color LEDs; 2) monolithic two-color cavity LEDs; and 3) filtered single-color cavity LEDs combined spatially. Performance metrics, such as power-to-temperature efficiency and radiance-to-crosstalk ratios, are compared across designs. Incorporation of cavities narrows emission, improves spectral radiance by 5–$10times $ and overlap with the emission band, lowers power requirements by ~2–$3times $ , and can reduce crosstalk. In-band to cross-band radiance ratio is generally limited to around 10–$1000times $ for monolithic two-color devices; two single color devices allow external filtering which improves the ratio to $10^{5}$ –$10^{7}$ . Results provide a framework for use of mid-infrared LEDs in multi-gas sensing and two-color mid-infrared LED arrays.
{"title":"Color Crosstalk in Two-Color Mid-Infrared LEDs With and Without Cavity Enhancement","authors":"David A. Montealegre;Weitao Dai;Matthew Z. Bellus;Logan M. Nichols;John P. Prineas","doi":"10.1109/JQE.2025.3586201","DOIUrl":"https://doi.org/10.1109/JQE.2025.3586201","url":null,"abstract":"Mid-infrared (3–<inline-formula> <tex-math>$5~mu $ </tex-math></inline-formula>m) LEDs have assumed greater importance optical gas sensors and have been explored for use in midinfrared LED arrays, in both cases to replace thermal pixels. Compared to thermal pixels, mid-infrared LEDs have near instantaneous settling times, achieve higher radiance, can have multi-spectral output, and are safer. Multispectral output creates the possibility of emission into narrowed bands for either sensing multiple gas species or creating dual emission thermal pixel arrays. However, their adoption for these applications is hindered by spectral crosstalk from emission tails at room temperature, and additionally by low efficiency, problematic in dense LED arrays with strict power density requirements. This work explores three approaches to designing two-color mid-infrared LED arrays, targeting reduced spectral crosstalk and lower power requirements: 1) monolithic two-color LEDs; 2) monolithic two-color cavity LEDs; and 3) filtered single-color cavity LEDs combined spatially. Performance metrics, such as power-to-temperature efficiency and radiance-to-crosstalk ratios, are compared across designs. Incorporation of cavities narrows emission, improves spectral radiance by 5–<inline-formula> <tex-math>$10times $ </tex-math></inline-formula> and overlap with the emission band, lowers power requirements by ~2–<inline-formula> <tex-math>$3times $ </tex-math></inline-formula>, and can reduce crosstalk. In-band to cross-band radiance ratio is generally limited to around 10–<inline-formula> <tex-math>$1000times $ </tex-math></inline-formula> for monolithic two-color devices; two single color devices allow external filtering which improves the ratio to <inline-formula> <tex-math>$10^{5}$ </tex-math></inline-formula>–<inline-formula> <tex-math>$10^{7}$ </tex-math></inline-formula>. Results provide a framework for use of mid-infrared LEDs in multi-gas sensing and two-color mid-infrared LED arrays.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"61 4","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144725242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we demonstrate a high-performance passively mode-locked thulium-holmium (Tm-Ho) co-doped fiber laser utilizing a single-mode fiber-few-mode fiber-single-mode fiber (SMF-FMF-SMF) structure as an effective saturable absorber (SA) for noise-like pulse (NLP) generation. By solely adjusting the output coupling ratio from 30% to 50%, the maximum average output power at a pump power of 4.5 W is significantly increased from 238 mW to 391.2 mW in a single-pulse operation. The corresponding maximum pulse energy reaches 99.5 nJ at a repetition rate of 3.933 MHz, with a broad 3 dB bandwidth of 33.40 nm centered at 1948 nm. The laser exhibits excellent stability, as evidenced by a signal-to-noise ratio (SNR) of 69 dB. These results highlight the effectiveness of the SMF-FMF-SMF structure in improving output power and pulse characteristics, offering a promising approach for advancing high-energy mode-locked fiber lasers.
{"title":"High-Power Noise-Like Pulse Generation in a Tm-Ho Co-Doped Fiber Laser","authors":"Longwei Luo;Huanhuan Li;Xinhao Zhou;Can Li;Junjie Zhang;Shiqing Xu","doi":"10.1109/JQE.2025.3584001","DOIUrl":"https://doi.org/10.1109/JQE.2025.3584001","url":null,"abstract":"In this study, we demonstrate a high-performance passively mode-locked thulium-holmium (Tm-Ho) co-doped fiber laser utilizing a single-mode fiber-few-mode fiber-single-mode fiber (SMF-FMF-SMF) structure as an effective saturable absorber (SA) for noise-like pulse (NLP) generation. By solely adjusting the output coupling ratio from 30% to 50%, the maximum average output power at a pump power of 4.5 W is significantly increased from 238 mW to 391.2 mW in a single-pulse operation. The corresponding maximum pulse energy reaches 99.5 nJ at a repetition rate of 3.933 MHz, with a broad 3 dB bandwidth of 33.40 nm centered at 1948 nm. The laser exhibits excellent stability, as evidenced by a signal-to-noise ratio (SNR) of 69 dB. These results highlight the effectiveness of the SMF-FMF-SMF structure in improving output power and pulse characteristics, offering a promising approach for advancing high-energy mode-locked fiber lasers.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"61 4","pages":"1-5"},"PeriodicalIF":2.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144725207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Semiconductor lasers are examined in the presence of quantum noise emanated from the gain medium. A pendulum-type, third order differential law for the phase of electric field is employed and the optical power spectrum of the system is rigorously derived as a sum of Lorentzians. The influence of injection level, linewidth enhancement factor, input detuning, and noise strength on the photonic oscillator response is identified. The followed methodology paves the way towards the analytical treatment of quantum noise effect in multiple photonic integrated circuits hosting tunable limit cycles, powerful resonances, and associated hysteresis phenomena.
{"title":"Quantum Noise on the Optical Power Spectra of Photonic Oscillators","authors":"Constantinos Valagiannopoulos;Athanasios Gavrielides;Vassilios Kovanis","doi":"10.1109/JQE.2025.3583999","DOIUrl":"https://doi.org/10.1109/JQE.2025.3583999","url":null,"abstract":"Semiconductor lasers are examined in the presence of quantum noise emanated from the gain medium. A pendulum-type, third order differential law for the phase of electric field is employed and the optical power spectrum of the system is rigorously derived as a sum of Lorentzians. The influence of injection level, linewidth enhancement factor, input detuning, and noise strength on the photonic oscillator response is identified. The followed methodology paves the way towards the analytical treatment of quantum noise effect in multiple photonic integrated circuits hosting tunable limit cycles, powerful resonances, and associated hysteresis phenomena.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"61 4","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144725203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thermal effects and stress play important roles in both performance and reliability of GaN-based laser diodes, particularly in multi-ridge lasers designed for high-power applications. In this paper, we studied the temperature and stress distributions within a five-ridge GaN-based laser diode. In the cross-ridge direction, the laser chip with a ridge spacing configuration of 64-76-76-$64~mu $ m exhibited the best temperature uniformity while an isometric ridge spacing of $60~mu $ m demonstrated the best stress uniformity. Furthermore, we proposed a tapered heatsink design to enhance the temperature and stress uniformity along the ridge. Our results indicated that, in comparison with the conventional structure, the tapered heatsink reduced the temperature difference along the ridge by 59%, leading to relatively lower temperature at both facets. Additionally, the tapered heatsink reduced the average stress by 26%. This study provides theoretical foundations and practical guidelines for the thermal and stress design of semiconductor lasers.
{"title":"Thermal and Stress Analysis on Multi-Ridge GaN-Based Laser Diodes","authors":"Minghang Liang;Jiahao Dong;Yu He;Jingxian Liang;Pengyan Wen","doi":"10.1109/JQE.2025.3583998","DOIUrl":"https://doi.org/10.1109/JQE.2025.3583998","url":null,"abstract":"Thermal effects and stress play important roles in both performance and reliability of GaN-based laser diodes, particularly in multi-ridge lasers designed for high-power applications. In this paper, we studied the temperature and stress distributions within a five-ridge GaN-based laser diode. In the cross-ridge direction, the laser chip with a ridge spacing configuration of 64-76-76-<inline-formula> <tex-math>$64~mu $ </tex-math></inline-formula> m exhibited the best temperature uniformity while an isometric ridge spacing of <inline-formula> <tex-math>$60~mu $ </tex-math></inline-formula> m demonstrated the best stress uniformity. Furthermore, we proposed a tapered heatsink design to enhance the temperature and stress uniformity along the ridge. Our results indicated that, in comparison with the conventional structure, the tapered heatsink reduced the temperature difference along the ridge by 59%, leading to relatively lower temperature at both facets. Additionally, the tapered heatsink reduced the average stress by 26%. This study provides theoretical foundations and practical guidelines for the thermal and stress design of semiconductor lasers.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"61 4","pages":"1-5"},"PeriodicalIF":2.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144725205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Performances of In0.75 Ga0.25 As focal plane arrays (FPAs) with an extended cutoff wavelength of $2.2~mu $ m are remarkably improved by largely increasing the overshooting composition of the linearly-grading Inx Al${}_{text {1-x}}$ As buffer layer. Zinc-diffused planar $640times 488$ FPAs with a pixel pitch of $23~mu $ m are fabricated on both the regular and the large overshooting epi-wafers with x=0.77 and x=0.85 for the end compositions of the linearly-grading Inx Al${}_{text {1-x}}$ As, respectively. An order of magnitude lower dark current density of $1.1 times 10 ^{-10}$ A/cm2 is achieved at 150 K for the large overshooting FPAs when comparing with $2.1times 10 ^{-9}$ A/cm2 for the regular FPAs. Suppressed dark signal and dark noise voltages are observed simultaneously over the measured whole integration time range. Moreover, the measured non-uniformity of the light response signal voltage drastically dropped from 16.4% to 2.9% while the peak detectivity substantially jumped from $7.1 times 10 ^{12}$ to $1.8 times 10 ^{13}$ cmHz${}^{1/2}$ W−1. A signal to noise ratio enhanced laboratory imaging demonstration is also provided. These results suggest the large overshooting epitaxial technology can serve as a highly viable route for the lattice-mismatched Inx Ga${}_{text {1-x}}$ As FPAs towards further performance enhancement.
通过大幅度增加线性级配Inx Al ${}_{text {1-x}}$ As缓冲层的过冲成分，可以显著提高截止波长为$2.2~mu $ m的In0.75 Ga0.25 As焦平面阵列（fpa）的性能。在线性级配Inx Al ${}_{text {1-x}}$ As的末端成分x=0.77和x=0.85条件下，在常规和大过冲外延晶片上分别制备了像素间距为$23~ $ mu $ m的$640 × 488$平面fpa。与常规fpa的2.1 × 10 ^{-9}$ A/cm2相比，大过冲fpa在150k时的暗电流密度降低了一个数量级，为1.1 × 10 ^{-10}$ A/cm2。在测量的整个积分时间范围内，同时观察到被抑制的暗信号和暗噪声电压。此外，测量到的光响应信号电压的非均匀性从16.4%急剧下降到2.9%，而峰值探测率从$7.1 times 10 ^{12}$ cmHz ${}^{1/2}$ W−1大幅上升到$1.8 times 10 ^{13}$ cmHz ${}^{1/2}$ W−1。还提供了增强信噪比的实验室成像演示。这些结果表明，大过冲外延技术可以作为晶格不匹配的Inx Ga ${}_{text {1-x}}$ fpa进一步提高性能的高度可行的途径。
{"title":"Enhanced Performance of Extended Wavelength InxGa1–xAs Focal Plane Arrays via Compositional Overshooting of InxAl1–xAs Buffer Layer","authors":"Xiaojuan Chen;Bowen Liu;Jifeng Cheng;Liyi Yang;Runze Xia;Yingjie Ma;Xiumei Shao;Yi Gu;Xue Li;Haimei Gong;Jiaxiong Fang","doi":"10.1109/JQE.2025.3583238","DOIUrl":"https://doi.org/10.1109/JQE.2025.3583238","url":null,"abstract":"Performances of In0.75 Ga0.25 As focal plane arrays (FPAs) with an extended cutoff wavelength of <inline-formula> <tex-math>$2.2~mu $ </tex-math></inline-formula>m are remarkably improved by largely increasing the overshooting composition of the linearly-grading Inx Al<inline-formula> <tex-math>${}_{text {1-x}}$ </tex-math></inline-formula> As buffer layer. Zinc-diffused planar <inline-formula> <tex-math>$640times 488$ </tex-math></inline-formula> FPAs with a pixel pitch of <inline-formula> <tex-math>$23~mu $ </tex-math></inline-formula>m are fabricated on both the regular and the large overshooting epi-wafers with x=0.77 and x=0.85 for the end compositions of the linearly-grading Inx Al<inline-formula> <tex-math>${}_{text {1-x}}$ </tex-math></inline-formula> As, respectively. An order of magnitude lower dark current density of <inline-formula> <tex-math>$1.1 times 10 ^{-10}$ </tex-math></inline-formula> A/cm2 is achieved at 150 K for the large overshooting FPAs when comparing with <inline-formula> <tex-math>$2.1times 10 ^{-9}$ </tex-math></inline-formula> A/cm2 for the regular FPAs. Suppressed dark signal and dark noise voltages are observed simultaneously over the measured whole integration time range. Moreover, the measured non-uniformity of the light response signal voltage drastically dropped from 16.4% to 2.9% while the peak detectivity substantially jumped from <inline-formula> <tex-math>$7.1 times 10 ^{12}$ </tex-math></inline-formula> to <inline-formula> <tex-math>$1.8 times 10 ^{13}$ </tex-math></inline-formula> cmHz<inline-formula> <tex-math>${}^{1/2}$ </tex-math></inline-formula>W−1. A signal to noise ratio enhanced laboratory imaging demonstration is also provided. These results suggest the large overshooting epitaxial technology can serve as a highly viable route for the lattice-mismatched Inx Ga<inline-formula> <tex-math>${}_{text {1-x}}$ </tex-math></inline-formula> As FPAs towards further performance enhancement.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"61 4","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144725204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：