High-performance 808-nm five-junction vertical cavity surface emitting lasers (VCSELs) are designed and fabricated. The light-current-voltage characteristics of the 808-nm five-junction and single-junction VCSELs are compared. The 808-nm five-junction VCSELs with a high slope efficiency of 5.92 W/A at $5~^{circ }$ C and 5.10 W/A at $25~^{circ }$ C are achieved. The maximum power conversion efficiency is 55.04% for the 808-nm five-junction individual VCSEL. Under short pulse conditions (400 Hz, 60 ns pulse width), the peak output power of the five-junction VCSELs array is 1.013 kW at 224 A. Such multi-junction 808 nm VCSELs with a high power density have important applications in Q-tuned solid-state lasers.
{"title":"High Power Multi-Junction 808 nm Vertical Cavity Surface Emitting Lasers With High Efficiency","authors":"Fansheng Meng;Hongwei Qu;Xuyan Zhou;Aiyi Qi;Jiatong Sui;Wanhua Zheng","doi":"10.1109/LPT.2024.3498439","DOIUrl":"https://doi.org/10.1109/LPT.2024.3498439","url":null,"abstract":"High-performance 808-nm five-junction vertical cavity surface emitting lasers (VCSELs) are designed and fabricated. The light-current-voltage characteristics of the 808-nm five-junction and single-junction VCSELs are compared. The 808-nm five-junction VCSELs with a high slope efficiency of 5.92 W/A at \u0000<inline-formula> <tex-math>$5~^{circ }$ </tex-math></inline-formula>\u0000C and 5.10 W/A at \u0000<inline-formula> <tex-math>$25~^{circ }$ </tex-math></inline-formula>\u0000C are achieved. The maximum power conversion efficiency is 55.04% for the 808-nm five-junction individual VCSEL. Under short pulse conditions (400 Hz, 60 ns pulse width), the peak output power of the five-junction VCSELs array is 1.013 kW at 224 A. Such multi-junction 808 nm VCSELs with a high power density have important applications in Q-tuned solid-state lasers.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"36 24","pages":"1489-1492"},"PeriodicalIF":2.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679360","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 : 2024-11-12DOI: 10.1109/LPT.2024.3496509
Weihua Shi;Xi Cheng;Yuyan Fan;Yuying Gu
In this letter, a dual-channel sensing structure for deoxyribonucleic acid (DNA) concentration and temperature is proposed. A gold coating is applied to the fiber’s exterior, creating a surface plasmon resonance (SPR) sensing channel for DNA concentration measurement. The diameter of the air holes in the innermost and central horizontal layers is reduced, which is conducive to achieving strong coupling between the core and surface plasmon mode. Additionally, toluene is filled into an air hole within the fiber cladding, thus establishing a directional coupled sensing channel specifically designed for temperature detection, which minimizes the effect of temperature on the concentration of DNA. The sensing structure’s performance is analyzed using the finite element method, and its parameters are optimized accordingly. The results show that the two sensing channels are independent of each other, the concentration sensitivity is 1.03 nm/ g $cdot $ cm $^{mathrm {-3}}$ at DNA concentration ranging from 0.029 to 0.248 g/cm3, and −9.75 nm/°C at temperatures ranging from 0 to $50~^{circ }$ C. The proposed sensing structure offers high sensitivity for DNA concentration and temperature detection, making it applicable in biomedical and other fields.
本文提出了一种用于脱氧核糖核酸（DNA）浓度和温度的双通道传感结构。在光纤的外部涂上一层金，形成一个用于测量 DNA 浓度的表面等离子体共振 (SPR) 传感通道。最内层和中央水平层的气孔直径减小，这有利于实现核心和表面等离子体模式之间的强耦合。此外，在光纤包层内的气孔中注入甲苯，从而建立了一个专门用于温度检测的定向耦合传感通道，将温度对 DNA 浓度的影响降至最低。利用有限元法分析了传感结构的性能，并对其参数进行了相应的优化。结果表明，两个传感通道相互独立，在 DNA 浓度为 0.029~0.248 g/cm3 时，浓度灵敏度为 1.03 nm/ g $cdot $ cm $^{mathrm {-3}}$；在温度为 0~50~^{circ }$ C 时，浓度灵敏度为 -9.75 nm/°C。
{"title":"Externally Coated Dual-Channel Photonic Crystal Fiber for Bio-Temperature Sensing","authors":"Weihua Shi;Xi Cheng;Yuyan Fan;Yuying Gu","doi":"10.1109/LPT.2024.3496509","DOIUrl":"https://doi.org/10.1109/LPT.2024.3496509","url":null,"abstract":"In this letter, a dual-channel sensing structure for deoxyribonucleic acid (DNA) concentration and temperature is proposed. A gold coating is applied to the fiber’s exterior, creating a surface plasmon resonance (SPR) sensing channel for DNA concentration measurement. The diameter of the air holes in the innermost and central horizontal layers is reduced, which is conducive to achieving strong coupling between the core and surface plasmon mode. Additionally, toluene is filled into an air hole within the fiber cladding, thus establishing a directional coupled sensing channel specifically designed for temperature detection, which minimizes the effect of temperature on the concentration of DNA. The sensing structure’s performance is analyzed using the finite element method, and its parameters are optimized accordingly. The results show that the two sensing channels are independent of each other, the concentration sensitivity is 1.03 nm/ g\u0000<inline-formula> <tex-math>$cdot $ </tex-math></inline-formula>\u0000cm\u0000<inline-formula> <tex-math>$^{mathrm {-3}}$ </tex-math></inline-formula>\u0000 at DNA concentration ranging from 0.029 to 0.248 g/cm3, and −9.75 nm/°C at temperatures ranging from 0 to \u0000<inline-formula> <tex-math>$50~^{circ }$ </tex-math></inline-formula>\u0000C. The proposed sensing structure offers high sensitivity for DNA concentration and temperature detection, making it applicable in biomedical and other fields.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"36 24","pages":"1493-1496"},"PeriodicalIF":2.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679314","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 increasing demand for high-speed and energy-efficient data transmission in global communication networks has driven the development of advanced optical interconnect technologies. This work explores the integration of an optical transmitter utilizing silicon photonic Mach-Zehnder modulators (MZMs) and drivers through a wire-bonding package. Fabricated on a silicon-on-insulator (SOI) platform, the MZMs leverage a single-drive series push-pull design to achieve high-speed modulation up to 112 Gbps and a 37 GHz bandwidth at a 3 V reverse DC bias, along with a modulation efficiency of 2.16 V $cdot $ cm. The transmitter architecture incorporates a four-channel driver array, and experimental results demonstrate a bandwidth of 46 GHz with the capability to deliver a total data rate beyond 200 Gbps. An optimized photonic-electronic co-design on optoelectronic chips holds the promise of facilitating higher data transmission rates.
{"title":"Optimized Photonic-Electronic Co-Design for Hybrid Integrated Silicon-Based Optical Transmitters","authors":"Daofa Wang;Ye Jin;Han Liu;Yingjie Ma;Ang Li;Yujun Xie;Menghan Yang;Guike Li;Yang Qu;Peng Wang;Ye Xiao;Jinping Guo;Rui Yang;Wei Li;Nan Qi;Ming Li","doi":"10.1109/LPT.2024.3496088","DOIUrl":"https://doi.org/10.1109/LPT.2024.3496088","url":null,"abstract":"The increasing demand for high-speed and energy-efficient data transmission in global communication networks has driven the development of advanced optical interconnect technologies. This work explores the integration of an optical transmitter utilizing silicon photonic Mach-Zehnder modulators (MZMs) and drivers through a wire-bonding package. Fabricated on a silicon-on-insulator (SOI) platform, the MZMs leverage a single-drive series push-pull design to achieve high-speed modulation up to 112 Gbps and a 37 GHz bandwidth at a 3 V reverse DC bias, along with a modulation efficiency of 2.16 V\u0000<inline-formula> <tex-math>$cdot $ </tex-math></inline-formula>\u0000 cm. The transmitter architecture incorporates a four-channel driver array, and experimental results demonstrate a bandwidth of 46 GHz with the capability to deliver a total data rate beyond 200 Gbps. An optimized photonic-electronic co-design on optoelectronic chips holds the promise of facilitating higher data transmission rates.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"36 24","pages":"1473-1476"},"PeriodicalIF":2.3,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672205","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}
We present an 850-nm VCSEL SPICE model that can be easily used for VCSEL simulation together with driver circuits. Our model consists of piece-wise linear RLC elements, whose bias-dependent parameter values are determined from measurement, and its configuration is determined with consideration for modeling and simulation convenience. The accuracy of the model is confirmed by comparing simulation results with the measurement results for the single-bit responses and the eye diagrams.
{"title":"A Large-Signal SPICE Model for VCSEL Based on Piece-Wise Linear RLC Elements","authors":"Kihun Kim;Jun-Seo Kim;Jae-Young Kim;Woo-Young Choi","doi":"10.1109/LPT.2024.3493956","DOIUrl":"https://doi.org/10.1109/LPT.2024.3493956","url":null,"abstract":"We present an 850-nm VCSEL SPICE model that can be easily used for VCSEL simulation together with driver circuits. Our model consists of piece-wise linear RLC elements, whose bias-dependent parameter values are determined from measurement, and its configuration is determined with consideration for modeling and simulation convenience. The accuracy of the model is confirmed by comparing simulation results with the measurement results for the single-bit responses and the eye diagrams.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"36 24","pages":"1477-1480"},"PeriodicalIF":2.3,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672133","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 : 2024-11-05DOI: 10.1109/LPT.2024.3491805
Bin Zhang;Zeyu Yu;Qishen Liang;Zichao Zhao;Bei Chen;Tingge Dai;Kun Yin;Hui Yu;Yuehai Wang;Jianyi Yang
We demonstrate a disaggregated optically-connected memory (OCM) architecture that supports dynamic resource allocation. Our proposed architecture utilizes a hitless wavelength-selective switch (WSS) based on silicon photonic (SiP) micro-ring resonators (MRRs) embedded with an equal-armed Mach-Zehnder interferometer, which permits a hitless rerouting of multi-wavelength signals. Error-free operation is achieved between a CPU node and two remote memory nodes using silicon photonic switch fabrics, showing the potential of integrating the photonic switched optically connected memory pools to the large-scale data centers and high performance computing (HPC) systems.
{"title":"Demonstration of Optically Connected Disaggregated Memory With Hitless Wavelength-Selective Switch","authors":"Bin Zhang;Zeyu Yu;Qishen Liang;Zichao Zhao;Bei Chen;Tingge Dai;Kun Yin;Hui Yu;Yuehai Wang;Jianyi Yang","doi":"10.1109/LPT.2024.3491805","DOIUrl":"https://doi.org/10.1109/LPT.2024.3491805","url":null,"abstract":"We demonstrate a disaggregated optically-connected memory (OCM) architecture that supports dynamic resource allocation. Our proposed architecture utilizes a hitless wavelength-selective switch (WSS) based on silicon photonic (SiP) micro-ring resonators (MRRs) embedded with an equal-armed Mach-Zehnder interferometer, which permits a hitless rerouting of multi-wavelength signals. Error-free operation is achieved between a CPU node and two remote memory nodes using silicon photonic switch fabrics, showing the potential of integrating the photonic switched optically connected memory pools to the large-scale data centers and high performance computing (HPC) systems.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"36 24","pages":"1485-1488"},"PeriodicalIF":2.3,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10744561","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An energy/area-efficient low-cost broadband linearity enhancement technique using the hybrid of notch-filter and bandpass-filter micro-ring modulators (Hybrid-MRMs) is proposed to achieve higher than 3.01-dB improvement in spurious-free-dynamic-ranges with intermodulation distortions ( $Delta $ SFDR $_{mathrm {IMD}}$ ) and 17.9-dB improvement in integral nonlinearity ( $Delta $ INL $_{mathrm {PP}}$ ) over a conventional notch-filter MRM (NF-MRM) across a 4.8-dB extinction-ratio full-scale range based on rapid silicon-photonics fabrication results for the emerging applications of various analog and digital optical communication systems.
{"title":"Micro-Ring Modulator Linearity Enhancement for Analog and Digital Optical Links","authors":"Sumilak Chaudhury;Karl Johnson;Vladimir Fedorov;Bill Lin;Yeshaiahu Fainman;Tzu-Chien Hsueh","doi":"10.1109/LPT.2024.3488699","DOIUrl":"https://doi.org/10.1109/LPT.2024.3488699","url":null,"abstract":"An energy/area-efficient low-cost broadband linearity enhancement technique using the hybrid of notch-filter and bandpass-filter micro-ring modulators (Hybrid-MRMs) is proposed to achieve higher than 3.01-dB improvement in spurious-free-dynamic-ranges with intermodulation distortions (\u0000<inline-formula> <tex-math>$Delta $ </tex-math></inline-formula>\u0000SFDR\u0000<inline-formula> <tex-math>$_{mathrm {IMD}}$ </tex-math></inline-formula>\u0000) and 17.9-dB improvement in integral nonlinearity (\u0000<inline-formula> <tex-math>$Delta $ </tex-math></inline-formula>\u0000INL\u0000<inline-formula> <tex-math>$_{mathrm {PP}}$ </tex-math></inline-formula>\u0000) over a conventional notch-filter MRM (NF-MRM) across a 4.8-dB extinction-ratio full-scale range based on rapid silicon-photonics fabrication results for the emerging applications of various analog and digital optical communication systems.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"36 24","pages":"1457-1460"},"PeriodicalIF":2.3,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595074","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}
We experimentally demonstrated the transmission of 300 GHz Delta-sigma Modulation (DSM) signals over Hollow-core fibers (HCF) and 2 m wireless links. By using dual-carrier modulation, we effectively improve the signal-to-noise ratio of the generated terahertz signal. At the same time, through HCF, we have successfully solved the problem of wavelength walk-off of optical terahertz (THz) signals caused by chromatic dispersion (CD) when transmitted in fiber links, and successfully demonstrated the transmission of a 24 Gbaud OOK-DSM signal over 2 km of HCF and 2 m of wireless links. The demonstration system supports mobile fronthaul (MFH) of 1024 QAM. At the same time, HCF is more suitable for delay-sensitive fronthaul links due to its low transmission delay characteristics. Therefore, the demonstrated system provides a promising scheme for MFH in areas where fiber is difficult to deploy.
{"title":"Dual Carrier Modulation 300 GHz DSM Terahertz Wave Signals Transmitted via Hollow-Core Fiber","authors":"Xiongwei Yang;Jianjun Yu;Xianming Zhao;Jingwen Tan;Yi Wei;Jiaxuan Liu;Feng Zhao;Kaihui Wang;Wen Zhou","doi":"10.1109/LPT.2024.3473913","DOIUrl":"https://doi.org/10.1109/LPT.2024.3473913","url":null,"abstract":"We experimentally demonstrated the transmission of 300 GHz Delta-sigma Modulation (DSM) signals over Hollow-core fibers (HCF) and 2 m wireless links. By using dual-carrier modulation, we effectively improve the signal-to-noise ratio of the generated terahertz signal. At the same time, through HCF, we have successfully solved the problem of wavelength walk-off of optical terahertz (THz) signals caused by chromatic dispersion (CD) when transmitted in fiber links, and successfully demonstrated the transmission of a 24 Gbaud OOK-DSM signal over 2 km of HCF and 2 m of wireless links. The demonstration system supports mobile fronthaul (MFH) of 1024 QAM. At the same time, HCF is more suitable for delay-sensitive fronthaul links due to its low transmission delay characteristics. Therefore, the demonstrated system provides a promising scheme for MFH in areas where fiber is difficult to deploy.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"36 24","pages":"1433-1436"},"PeriodicalIF":2.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587559","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}
Early studies suggest that absorption coefficient of GaN exceeds 100 cm−1 at wavelengths below 380 nm, indicating GaN might not be suitable as a waveguide (WG) material for laser diodes (LDs) in this range. However, in those studies, material defects (rather than GaN band edge absorption) could contribute significantly to the measured absorption loss. In this work, III-Nitride LDs emitting at 376 nm using unintentionally doped GaN WG was demonstrated for high-power operation. Devices with a cavity length of $750 ; mu $ m and a ridge width of $10 ; mu $ m exhibited a threshold current of 625 mA and a slope efficiency of 1.13 W/A under pulsed conditions. The highest output power of 3.4 W was obtained at an injection current of 3.5 A. These promising results suggest that GaN band edge absorption may not be as significant at 376 nm or even shorter wavelengths, allowing more flexibility in epitaxial design.
早期的研究表明，在波长低于 380 纳米时，氮化镓的吸收系数超过 100 cm-1，这表明氮化镓可能不适合用作此波长范围内激光二极管（LD）的波导（WG）材料。然而，在这些研究中，材料缺陷（而不是氮化镓带缘吸收）可能在很大程度上导致了测量到的吸收损耗。在这项工作中，使用无意掺杂的 GaN WG 的 III 氮化物 LD 在 376 纳米波长发射，实现了高功率运行。空腔长度为 750 ; mu $ m、脊宽为 10 ; mu $ m 的器件在脉冲条件下的阈值电流为 625 mA，斜率效率为 1.13 W/A。这些令人鼓舞的结果表明，GaN 带缘吸收在 376 纳米甚至更短的波长下可能并不那么明显，从而使外延设计更具灵活性。
{"title":"376 nm High-Power UV-A Laser Diodes With GaN Waveguide","authors":"Qinchen Lin;Cheng Liu;Guangying Wang;Surjava Sanyal;Matthew Dwyer;Matthew Seitz;Jiahao Chen;Yuting Li;Tom Earles;Nelson Tansu;Jing Zhang;Luke Mawst;Chirag Gupta;Shubhra S. Pasayat","doi":"10.1109/LPT.2024.3488037","DOIUrl":"https://doi.org/10.1109/LPT.2024.3488037","url":null,"abstract":"Early studies suggest that absorption coefficient of GaN exceeds 100 cm−1 at wavelengths below 380 nm, indicating GaN might not be suitable as a waveguide (WG) material for laser diodes (LDs) in this range. However, in those studies, material defects (rather than GaN band edge absorption) could contribute significantly to the measured absorption loss. In this work, III-Nitride LDs emitting at 376 nm using unintentionally doped GaN WG was demonstrated for high-power operation. Devices with a cavity length of \u0000<inline-formula> <tex-math>$750 ; mu $ </tex-math></inline-formula>\u0000m and a ridge width of \u0000<inline-formula> <tex-math>$10 ; mu $ </tex-math></inline-formula>\u0000m exhibited a threshold current of 625 mA and a slope efficiency of 1.13 W/A under pulsed conditions. The highest output power of 3.4 W was obtained at an injection current of 3.5 A. These promising results suggest that GaN band edge absorption may not be as significant at 376 nm or even shorter wavelengths, allowing more flexibility in epitaxial design.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"36 24","pages":"1449-1452"},"PeriodicalIF":2.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594938","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}
Realizing a mid-infrared (mid-IR) nonreciprocal thermal emitter (NTE) within atmospheric window is a promising yet challenging task. Here we theoretically explore the enhanced contrast between emission and absorption of a resonant system with Weyl semimetal (WSM). We propose and present a lithography-free approach for manipulating the nonreciprocal thermal radiation (NTR), which also leads to near-zero emission and near-unity absorption simultaneously. It shows that the reciprocity between absorption and emission can be strongly broken with the difference of 0.973 at wavelength of $13.6~mu m$ . By examining the impact of geometrical parameters, the structure manifests large parameter tolerance, which is advantageous for practical fabrication and application. The influence of incidence angle and azimuthal angle on the nonreciprocity has been also been investigated. The presented results offer new insights into engineering absorption and emission, that can facilitate the design of NTE in the mid-IR region.
{"title":"Strong Nonreciprocal Thermal Radiation Within Atmospheric Window With Lithography-Free Structure","authors":"Xin Cui;Yantong Shen;Liming Qian;Shixin Pei;Gaige Zheng","doi":"10.1109/LPT.2024.3487769","DOIUrl":"https://doi.org/10.1109/LPT.2024.3487769","url":null,"abstract":"Realizing a mid-infrared (mid-IR) nonreciprocal thermal emitter (NTE) within atmospheric window is a promising yet challenging task. Here we theoretically explore the enhanced contrast between emission and absorption of a resonant system with Weyl semimetal (WSM). We propose and present a lithography-free approach for manipulating the nonreciprocal thermal radiation (NTR), which also leads to near-zero emission and near-unity absorption simultaneously. It shows that the reciprocity between absorption and emission can be strongly broken with the difference of 0.973 at wavelength of \u0000<inline-formula> <tex-math>$13.6~mu m$ </tex-math></inline-formula>\u0000. By examining the impact of geometrical parameters, the structure manifests large parameter tolerance, which is advantageous for practical fabrication and application. The influence of incidence angle and azimuthal angle on the nonreciprocity has been also been investigated. The presented results offer new insights into engineering absorption and emission, that can facilitate the design of NTE in the mid-IR region.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"36 24","pages":"1445-1448"},"PeriodicalIF":2.3,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595127","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 efficient recognition of topological charge (TC) is an essential function for vortex beams-based applications. However, image acquisition devices and image processing algorithms are always demanded by conventional diffraction- or interference-based methods. In this study, we have proposed a frequency measurement method to recognize the amplitude of TC by using rotating slits and photodetectors (PDs) instead of image acquisition devices. In addition, the sign of TC for the conjugated vortex beams can be identified using a designed optical structure, which is composed of vortex retarders and conjugated vortex beams-based Mach-Zehnder interferometers (CVMZIs). The experimental results show the vortex beams with TC varying from -6 to +6 can been efficiently recognized, indicating the feasibility of the proposed method. To our knowledge, this is the first time that the recognition of amplitude and sign of TC of vortex beams has been realized using PD-based simple structure. Since no additional diffraction devices, image acquisition devices with limited sampling rate and resolution, and complex image processing algorithms are required, the proposed method can recognize TC of vortex beams low-costly, efficiently, precisely, and automatically, which may further promote and develop the TC recognition method for vortex beams.
{"title":"Topological Charge Recognition of Vortex Beams Using PDs","authors":"Jiayang Xu;Zhenyu Ma;Ming Gao;Yutao Wang;Dongmei Guo;Huali Lu;Hua Zhao","doi":"10.1109/LPT.2024.3487583","DOIUrl":"https://doi.org/10.1109/LPT.2024.3487583","url":null,"abstract":"The efficient recognition of topological charge (TC) is an essential function for vortex beams-based applications. However, image acquisition devices and image processing algorithms are always demanded by conventional diffraction- or interference-based methods. In this study, we have proposed a frequency measurement method to recognize the amplitude of TC by using rotating slits and photodetectors (PDs) instead of image acquisition devices. In addition, the sign of TC for the conjugated vortex beams can be identified using a designed optical structure, which is composed of vortex retarders and conjugated vortex beams-based Mach-Zehnder interferometers (CVMZIs). The experimental results show the vortex beams with TC varying from -6 to +6 can been efficiently recognized, indicating the feasibility of the proposed method. To our knowledge, this is the first time that the recognition of amplitude and sign of TC of vortex beams has been realized using PD-based simple structure. Since no additional diffraction devices, image acquisition devices with limited sampling rate and resolution, and complex image processing algorithms are required, the proposed method can recognize TC of vortex beams low-costly, efficiently, precisely, and automatically, which may further promote and develop the TC recognition method for vortex beams.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"36 24","pages":"1461-1464"},"PeriodicalIF":2.3,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595062","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}
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