Pub Date : 2025-09-16DOI: 10.1109/JPHOT.2025.3610140
Ruisi Wang;Kaishuo Zhang;Jing Wei;Wei Zhao
The generation and modulation of vector beams typically require mechanical adjustments of optical components, leading to a complex setup and long manipulation times. In this work, we propose an electrically controllable approach to generate vector beams by integrating liquid crystal plates with a dielectric metasurface. The dielectric metasurface features continuously reoriented optical axis, enabling the generation of high-quality vector beams. Two homogeneous liquid crystal plates, with phase retardation adjustable through an externally applied voltage, allow precise control over the latitude and longitude of vector polarization states on the Poincaré sphere. Once the experimental setup is established, no mechanical adjustments are necessary. The combination of liquid crystal plates and dielectric metasurface extends the capabilities of polarization manipulations, which leads to a convenient and flexible way to generate any desirable vector beams. This work could find potential applications in quantum optics, optical imaging, and precision sensing, where dynamic and precise control of light is crucial for enhancing performance and enabling scientific functionalities.
{"title":"Electrically Tunable Generation of Vector Beams via Integrated Liquid Crystal Plates and Dielectric Metasurface","authors":"Ruisi Wang;Kaishuo Zhang;Jing Wei;Wei Zhao","doi":"10.1109/JPHOT.2025.3610140","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3610140","url":null,"abstract":"The generation and modulation of vector beams typically require mechanical adjustments of optical components, leading to a complex setup and long manipulation times. In this work, we propose an electrically controllable approach to generate vector beams by integrating liquid crystal plates with a dielectric metasurface. The dielectric metasurface features continuously reoriented optical axis, enabling the generation of high-quality vector beams. Two homogeneous liquid crystal plates, with phase retardation adjustable through an externally applied voltage, allow precise control over the latitude and longitude of vector polarization states on the Poincaré sphere. Once the experimental setup is established, no mechanical adjustments are necessary. The combination of liquid crystal plates and dielectric metasurface extends the capabilities of polarization manipulations, which leads to a convenient and flexible way to generate any desirable vector beams. This work could find potential applications in quantum optics, optical imaging, and precision sensing, where dynamic and precise control of light is crucial for enhancing performance and enabling scientific functionalities.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 5","pages":"1-5"},"PeriodicalIF":2.4,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11164666","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-12DOI: 10.1109/JPHOT.2025.3606696
Yahui Zhu;Ailing Tian;Hongjun Wang;Bingcai Liu
Lateral shearing interferometry is an effective method for directly measuring the depth gradient of aspherical surfaces. To address the low phase reconstruction accuracy resulting from the fact that lateral shear interferometers typically obtain only two sets of wavefront data in a single orthogonal direction, which leads to fewer sampling points, this paper presents an aspherical surface measurement method based on birefringent crystals and multi-directional lateral shearing phase-shifting interferometry. This method overcomes nonlinear issues and environmental influences during phase-shifting interferometry, captures shear wavefront data in multiple directions, and reconstructs the surface by solving for the wavefront coefficients using multi-directional differential wavefront information. It also reduces system random errors, improving surface reconstruction accuracy. We propose a multi-directional lateral shearing synchronous phase-shifting interferometry technique for measuring aspherical surfaces. The methodology includes multi-directional shearing, synchronous phase-shifting, crystal birefringence modulation, phase grating diffraction, and polarization phase-shifting arrays. An experimental system was built to test aspherical surface samples, and aspherical surface measurements were conducted on a surface with a 90 mm diameter, 606 mm vertex curvature radius, and a quadratic conic coefficient of −1. The deviation of the measured aspherical surface from the optimal spherical surface was obtained, and the initial deviation of the ideal aspherical surface from the optimal spherical surface was calculated using the ray tracing method. The repeated measurement results were consistent with those from the ZYGO interferometer’s self-collimation method, with an RMS deviation better than λ/100. The experiment demonstrated the effectiveness, repeatability and measurement stability of the multi-directional lateral shearing interferometry system for measuring aspherical surfaces.
{"title":"Aspherical Surface Measurement With Multi-Directional Lateral Shearing Phase-Shifting Interferometry","authors":"Yahui Zhu;Ailing Tian;Hongjun Wang;Bingcai Liu","doi":"10.1109/JPHOT.2025.3606696","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3606696","url":null,"abstract":"Lateral shearing interferometry is an effective method for directly measuring the depth gradient of aspherical surfaces. To address the low phase reconstruction accuracy resulting from the fact that lateral shear interferometers typically obtain only two sets of wavefront data in a single orthogonal direction, which leads to fewer sampling points, this paper presents an aspherical surface measurement method based on birefringent crystals and multi-directional lateral shearing phase-shifting interferometry. This method overcomes nonlinear issues and environmental influences during phase-shifting interferometry, captures shear wavefront data in multiple directions, and reconstructs the surface by solving for the wavefront coefficients using multi-directional differential wavefront information. It also reduces system random errors, improving surface reconstruction accuracy. We propose a multi-directional lateral shearing synchronous phase-shifting interferometry technique for measuring aspherical surfaces. The methodology includes multi-directional shearing, synchronous phase-shifting, crystal birefringence modulation, phase grating diffraction, and polarization phase-shifting arrays. An experimental system was built to test aspherical surface samples, and aspherical surface measurements were conducted on a surface with a 90 mm diameter, 606 mm vertex curvature radius, and a quadratic conic coefficient of −1. The deviation of the measured aspherical surface from the optimal spherical surface was obtained, and the initial deviation of the ideal aspherical surface from the optimal spherical surface was calculated using the ray tracing method. The repeated measurement results were consistent with those from the ZYGO interferometer’s self-collimation method, with an RMS deviation better than λ/100. The experiment demonstrated the effectiveness, repeatability and measurement stability of the multi-directional lateral shearing interferometry system for measuring aspherical surfaces.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 5","pages":"1-13"},"PeriodicalIF":2.4,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11162609","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose an estimation method of the relative position of a light emitting diode (LED) from a rolling-shutter (RS) camera with a cross filter (CF). The CF is set in front of the camera lens so that incident light can be scattered into two straight lines extending about $pm pi /4$ from the horizontal row of the CMOS RS image sensor (IS). With the geometry of a right-angled isosceles triangle, our method makes it possible to estimate the coordinates of the LED in the IS plane when the scattered light is captured at two points in a scanline. With the CF, our method continues to update the estimated coordinate of the LED as long as the row captures scattered light at two points. Naturally, our method makes it possible row by row when multiple LEDs are used or when they are moving. In contrast, without the CF, estimation is not possible until the scanline reaches the row which captures the whole LED, and the estimated coordinates are not updated once it is done for that frame. Experiments verify that our estimation method works with the estimation error less than five pixels, and extends the region of a frame in which estimated coordinates are output, even in a moving environment, while the conventional method (without CF) does the estimated coordinates only once per frame.
我们提出了一种利用交叉滤光片（CF）估算滚动快门（RS）相机中发光二极管（LED）相对位置的方法。CF设置在相机镜头的前面，这样入射光可以从CMOS RS图像传感器（is）的水平行散射成两条直线，延伸约$pm pi /4$。利用直角等腰三角形的几何形状，当散射光在扫描线的两点上被捕获时，我们的方法使得估计LED在IS平面上的坐标成为可能。使用CF，我们的方法继续更新LED的估计坐标，只要行捕获两点的散射光。当然，当多个led被使用或移动时，我们的方法可以逐行实现。相反，如果没有CF，在扫描线到达捕获整个LED的行之前，估计是不可能的，并且一旦完成该帧的估计坐标就不会更新。实验证明，该估计方法的估计误差小于5个像素，并且即使在运动环境中也可以扩展输出估计坐标的帧区域，而传统方法（不含CF）每帧只输出一次估计坐标。
{"title":"Relative Position Estimation Using Cross Filter for Rolling-Shutter Cameras","authors":"Daisuke Sekimoto;Koji Kamakura;Masayuki Kinoshita;Takaya Yamazato","doi":"10.1109/JPHOT.2025.3608630","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3608630","url":null,"abstract":"We propose an estimation method of the relative position of a light emitting diode (LED) from a rolling-shutter (RS) camera with a cross filter (CF). The CF is set in front of the camera lens so that incident light can be scattered into two straight lines extending about <inline-formula><tex-math>$pm pi /4$</tex-math></inline-formula> from the horizontal row of the CMOS RS image sensor (IS). With the geometry of a right-angled isosceles triangle, our method makes it possible to estimate the coordinates of the LED in the IS plane when the scattered light is captured at two points in a scanline. With the CF, our method continues to update the estimated coordinate of the LED as long as the row captures scattered light at two points. Naturally, our method makes it possible row by row when multiple LEDs are used or when they are moving. In contrast, without the CF, estimation is not possible until the scanline reaches the row which captures the whole LED, and the estimated coordinates are not updated once it is done for that frame. Experiments verify that our estimation method works with the estimation error less than five pixels, and extends the region of a frame in which estimated coordinates are output, even in a moving environment, while the conventional method (without CF) does the estimated coordinates only once per frame.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 5","pages":"1-9"},"PeriodicalIF":2.4,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11155154","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The integration of fiber and wireless communications presents a promising avenue to enhance communication networks, supporting the evolution of 5G-A/6G technologies, which includes upgrades to traditional access networks and mobile X-haul. We propose a point-to-multipoint (PtMP) coherent passive optical network (PON) architecture based on digital subcarrier multiplexing (DSCM) supporting fiber-wireless convergence scenarios as a promising solution for fixed and mobile access networks. The characteristics and potential applications of coherent PON, DSCM, and analog fiber-wireless transmission technologies are analyzed in the context of access networks. To evaluate our proposed scheme, we demonstrated a rate-flexible PtMP coherent PON architecture with downlink and uplink using DSCM to support fixed broadband access and W-band millimeter wave (mm-Wave) wireless access simultaneously. The architecture implements four 25G subcarriers for downstream and up to four 25G (fiber-wired) /12.5G (mm-Wave wireless) subcarriers for upstream, respectively. The results show that over 40 dB/42 dB power budget at SD-FEC threshold in fixed broadband access downstream/upstream transmission can be achieved, and over 34 dB/47 dB power budget in mm-Wave wireless access downstream/upstream (50G) transmission can be achieved, respectively. This scheme offers a favorable balance between system complexity and cost-effectiveness for next-generation optical networks and wireless access in the 5G-A/6G era.
{"title":"Demonstration of Bi-Directional Point-to-Multipoint Coherent PON Using Digital Subcarrier Multiplexing for Broadband Access and Wireless Fronthaul","authors":"Shuang Gao;Jiao Zhang;Yingxin Wei;Yutong Jiang;Zhuoxin Li;Bingchang Hua;Zhigang Xin;Qing Zhong;Yuancheng Cai;Mingzheng Lei;Junjie Ding;Xingyu Chen;Yucong Zou;Meihua Bi;Min Zhu","doi":"10.1109/JPHOT.2025.3608197","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3608197","url":null,"abstract":"The integration of fiber and wireless communications presents a promising avenue to enhance communication networks, supporting the evolution of 5G-A/6G technologies, which includes upgrades to traditional access networks and mobile X-haul. We propose a point-to-multipoint (PtMP) coherent passive optical network (PON) architecture based on digital subcarrier multiplexing (DSCM) supporting fiber-wireless convergence scenarios as a promising solution for fixed and mobile access networks. The characteristics and potential applications of coherent PON, DSCM, and analog fiber-wireless transmission technologies are analyzed in the context of access networks. To evaluate our proposed scheme, we demonstrated a rate-flexible PtMP coherent PON architecture with downlink and uplink using DSCM to support fixed broadband access and W-band millimeter wave (mm-Wave) wireless access simultaneously. The architecture implements four 25G subcarriers for downstream and up to four 25G (fiber-wired) /12.5G (mm-Wave wireless) subcarriers for upstream, respectively. The results show that over 40 dB/42 dB power budget at SD-FEC threshold in fixed broadband access downstream/upstream transmission can be achieved, and over 34 dB/47 dB power budget in mm-Wave wireless access downstream/upstream (50G) transmission can be achieved, respectively. This scheme offers a favorable balance between system complexity and cost-effectiveness for next-generation optical networks and wireless access in the 5G-A/6G era.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 5","pages":"1-11"},"PeriodicalIF":2.4,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11154858","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145141687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-09DOI: 10.1109/JPHOT.2025.3607986
Chia-Hsun Chen;Shu-Bai Liu;Ting-Chun Wang
In this work, a Ga2O3/p-Si MOS-type Schottky barrier photodetector was successfully fabricated and characterized for solar-blind ultraviolet detection. The electrical and optoelectronic characterizations of the devices were performed under dark and 254 nm illumination. The device performance metrics, including Schottky barrier height $( {{{Phi }_{B0}}} )$, ideality factor $( n )$, and series resistance $( {{{R}_s}} )$ were extracted employing Cheung’s method and Norde’s methods. Both methods revealed that UV illumination leads to reductions in the ideality factor and series resistance, indicating improved carrier transport and reduced recombination losses due to the generation of photo-induced carriers. In addition, under the 254 nm illumination and reverse bias of −5 V, the devices exhibited a maximum responsivity of 0.39 A/W and a corresponding external quantum efficiency ($EQE)$ of 193%. The noise-equivalent power ($NEP$) and detectivity ($D$) were 1.45×10−13 W and 6.89×1012 Jones, respectively, demonstrating the high sensitivity and potential of the Ga2O3/p-Si Schottky structure for deep UV sensing applications.
{"title":"Photosensitive Characteristics of Ga2O3/p-Si Schottky Barrier Solar-Blind Photodetector","authors":"Chia-Hsun Chen;Shu-Bai Liu;Ting-Chun Wang","doi":"10.1109/JPHOT.2025.3607986","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3607986","url":null,"abstract":"In this work, a Ga<sub>2</sub>O<sub>3</sub>/p-Si MOS-type Schottky barrier photodetector was successfully fabricated and characterized for solar-blind ultraviolet detection. The electrical and optoelectronic characterizations of the devices were performed under dark and 254 nm illumination. The device performance metrics, including Schottky barrier height <inline-formula><tex-math>$( {{{Phi }_{B0}}} )$</tex-math></inline-formula>, ideality factor <inline-formula><tex-math>$( n )$</tex-math></inline-formula>, and series resistance <inline-formula><tex-math>$( {{{R}_s}} )$</tex-math></inline-formula> were extracted employing Cheung’s method and Norde’s methods. Both methods revealed that UV illumination leads to reductions in the ideality factor and series resistance, indicating improved carrier transport and reduced recombination losses due to the generation of photo-induced carriers. In addition, under the 254 nm illumination and reverse bias of −5 V, the devices exhibited a maximum responsivity of 0.39 A/W and a corresponding external quantum efficiency (<inline-formula><tex-math>$EQE)$</tex-math></inline-formula> of 193%. The noise-equivalent power (<inline-formula><tex-math>$NEP$</tex-math></inline-formula>) and detectivity (<inline-formula><tex-math>$D$</tex-math></inline-formula>) were 1.45×10<sup>−13</sup> W and 6.89×10<sup>12</sup> Jones, respectively, demonstrating the high sensitivity and potential of the Ga<sub>2</sub>O<sub>3</sub>/p-Si Schottky structure for deep UV sensing applications.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 5","pages":"1-7"},"PeriodicalIF":2.4,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11154127","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145315408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thermo-optic (TO) switches are essential components in integrated photonic circuits (PICs), but their efficiency is limited by significant heat dissipation into the silicon substrate due to its high thermal conductivity. This study presents an energy-efficient TO switching solution based on 3D glass-based EIC–PIC packaging. By leveraging the low thermal conductivity of a glass interposer, the heater efficiency is significantly enhanced. Finite element simulations show that the hybrid-bonded PIC achieves a 3.43 times improvement in heater efficiency compared to conventional surface-mounted PICs, reaching 947.7 pm/mW. For a switch array with a through-glass via pitch of 100 μm, the normalized thermal crosstalk remains below 6% . The out-of-plane warpage is less than 1 μm for a 5 mm × 5 mm PIC. This 3D integration strategy provides a scalable and energy-efficient platform for high-density photonic switching, addressing key challenges in large-scale optical systems.
{"title":"Energy-Efficient Thermo-Optic Switches Enabled by 3D Glass-Based EIC–PIC Packaging for High-Density Photonic Switch Arrays","authors":"Zhonghua Yang;Qingji Zhao;Yuchi Yang;Guopeng He;Guosheng Yan;Songxuan Liu;Yufeng Li;Yu Sun;Wenbo Luo;Wanli Zhang","doi":"10.1109/JPHOT.2025.3607966","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3607966","url":null,"abstract":"Thermo-optic (TO) switches are essential components in integrated photonic circuits (PICs), but their efficiency is limited by significant heat dissipation into the silicon substrate due to its high thermal conductivity. This study presents an energy-efficient TO switching solution based on 3D glass-based EIC–PIC packaging. By leveraging the low thermal conductivity of a glass interposer, the heater efficiency is significantly enhanced. Finite element simulations show that the hybrid-bonded PIC achieves a 3.43 times improvement in heater efficiency compared to conventional surface-mounted PICs, reaching 947.7 pm/mW. For a switch array with a through-glass via pitch of 100 μm, the normalized thermal crosstalk remains below 6% . The out-of-plane warpage is less than 1 μm for a 5 mm × 5 mm PIC. This 3D integration strategy provides a scalable and energy-efficient platform for high-density photonic switching, addressing key challenges in large-scale optical systems.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 5","pages":"1-7"},"PeriodicalIF":2.4,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11153947","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-09DOI: 10.1109/JPHOT.2025.3607596
Yilin Zhong;Xiangyu Gao;Qiang Xu;Wei Wang;Shuxiao Wang;Yan Cai
We have demonstrated an eight-channel wavelength demultiplexer in the L-band based on a cascaded Mach-Zehnder interferometer (MZI) lattice filter fabricated on an 8-inch silicon nitride (SiN) photonics platform. A flat passband is achieved, and channel crosstalk is minimized through a cascaded three-stage MZI structure. The demultiplexing of eight targeted wavelengths within the range of 1580 nm to 1600 nm is successfully accomplished without requiring a thermo-optic phase shifter. For the best-performing device, the experimentally measured device insertion loss is less than 1.8 dB, the channel crosstalk is less than -18 dB, and the 1-dB bandwidth reaches 1.8 nm. On an 8-inch wafer, the average insertion loss and the worst crosstalk of the device are 1.8 dB and −14.8 dB, respectively. The demonstrated passive eight-channel demultiplexer provides a reliable solution for the L-band optical data communication.
{"title":"Flat-Top Eight-Channel Wavelength Division Demultiplexer for L-Band Optical Communication With Low Crosstalk","authors":"Yilin Zhong;Xiangyu Gao;Qiang Xu;Wei Wang;Shuxiao Wang;Yan Cai","doi":"10.1109/JPHOT.2025.3607596","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3607596","url":null,"abstract":"We have demonstrated an eight-channel wavelength demultiplexer in the L-band based on a cascaded Mach-Zehnder interferometer (MZI) lattice filter fabricated on an 8-inch silicon nitride (SiN) photonics platform. A flat passband is achieved, and channel crosstalk is minimized through a cascaded three-stage MZI structure. The demultiplexing of eight targeted wavelengths within the range of 1580 nm to 1600 nm is successfully accomplished without requiring a thermo-optic phase shifter. For the best-performing device, the experimentally measured device insertion loss is less than 1.8 dB, the channel crosstalk is less than -18 dB, and the 1-dB bandwidth reaches 1.8 nm. On an 8-inch wafer, the average insertion loss and the worst crosstalk of the device are 1.8 dB and −14.8 dB, respectively. The demonstrated passive eight-channel demultiplexer provides a reliable solution for the L-band optical data communication.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 5","pages":"1-6"},"PeriodicalIF":2.4,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11153803","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we demonstrate a free space optical (FSO) wavelength-division-multiplexing passive optical network (WDM-PON) architecture with short-reach to long-reach fiber transmission to overcome different environments and geographical restrictions. Based on the periodic nature of the 2×N arrayed waveguide grating (AWG), the downstream and upstream wavelengths in the proposed fiber access network are offset by one channel to enable symmetric FSO data transmission. Thus, the Rayleigh backscattering (RB) beat noise can be mitigated fully. Four WDM channels are selected to transmit wireless FSO signals over the proposed PON architecture, each utilizing different modulation rates and fiber transmission distances for demonstration. In addition, the corresponding bit error rate (BER), detected power sensitivity and power budget of each WDM FSO signal are also analyzed and discussed.
{"title":"Short- to Long-Reach WDM Access Network With Free Space Optical Traffic Link","authors":"Chien-Yu Liao;Tsu-Hsin Wu;Chien-Hung Yeh;Wen-Paio Lin;Yu-Heng Lin;Shien-Kuei Liaw","doi":"10.1109/JPHOT.2025.3608203","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3608203","url":null,"abstract":"In this paper, we demonstrate a free space optical (FSO) wavelength-division-multiplexing passive optical network (WDM-PON) architecture with short-reach to long-reach fiber transmission to overcome different environments and geographical restrictions. Based on the periodic nature of the 2×N arrayed waveguide grating (AWG), the downstream and upstream wavelengths in the proposed fiber access network are offset by one channel to enable symmetric FSO data transmission. Thus, the Rayleigh backscattering (RB) beat noise can be mitigated fully. Four WDM channels are selected to transmit wireless FSO signals over the proposed PON architecture, each utilizing different modulation rates and fiber transmission distances for demonstration. In addition, the corresponding bit error rate (BER), detected power sensitivity and power budget of each WDM FSO signal are also analyzed and discussed.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 5","pages":"1-5"},"PeriodicalIF":2.4,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11154880","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145100470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-08DOI: 10.1109/JPHOT.2025.3606953
Yang Yan;Chenyue He;Churui Li;Rui Jin;Yuzhe Sun;Chao Wang;Bo Jia
The Mach-Zehnder and Sagnac hybrid fiber optic interferometer (MZSI) is widely applied in numerous fields and capable of retrieving phase signals with the application of the appropriate demodulation algorithm. However, the performances of demodulation algorithms in MZSI are mainly evaluated based on empirical experiments. To address the lack of theory for selecting the optimal demodulation algorithm in MZSI, the noise transfer models of the differential cross multiplexing (DCM) and Arctangent (Atan) demodulation algorithms are investigated in both frequency and time domains. A novel analytical expression is proposed to characterize the noise transfer in the frequency domain, which accords with that in the time domain. The theoretical noise transfer models of the DCM and Atan demodulation are verified by simulation and experiment. The performance comparison between the DCM and Atan demodulation algorithms are conducted through the noise transfer models. It provides a reference for the selection of DCM and Atan demodulation algorithms in MZSI, which contributes to enhancing the demodulation performance of MZSI.
{"title":"Modeling Noise Transfer in Phase Demodulation Algorithm for Mach-Zehnder and Sagnac Hybrid Fiber Optic Interferometer","authors":"Yang Yan;Chenyue He;Churui Li;Rui Jin;Yuzhe Sun;Chao Wang;Bo Jia","doi":"10.1109/JPHOT.2025.3606953","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3606953","url":null,"abstract":"The Mach-Zehnder and Sagnac hybrid fiber optic interferometer (MZSI) is widely applied in numerous fields and capable of retrieving phase signals with the application of the appropriate demodulation algorithm. However, the performances of demodulation algorithms in MZSI are mainly evaluated based on empirical experiments. To address the lack of theory for selecting the optimal demodulation algorithm in MZSI, the noise transfer models of the differential cross multiplexing (DCM) and Arctangent (Atan) demodulation algorithms are investigated in both frequency and time domains. A novel analytical expression is proposed to characterize the noise transfer in the frequency domain, which accords with that in the time domain. The theoretical noise transfer models of the DCM and Atan demodulation are verified by simulation and experiment. The performance comparison between the DCM and Atan demodulation algorithms are conducted through the noise transfer models. It provides a reference for the selection of DCM and Atan demodulation algorithms in MZSI, which contributes to enhancing the demodulation performance of MZSI.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 5","pages":"1-7"},"PeriodicalIF":2.4,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11153034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quantum efficiency of deep-ultraviolet (DUV) light-emitting diodes (LEDs) is a roadblock for these devices to reach efficiencies comparable to their visible light counterparts. The main contributing factor limiting the internal quantum efficiency (IQE) are the effects of the quantum confined Stark effect (QCSE) and valance subband crossover, which can be mitigated through engineering of the quantum well (QW) active region. This work represents the first fabrication and testing of novel full structure electrically driven AlGaN-delta-GaN QW DUV micro-LEDs ($mu$LEDs) with mesa dimensions between 10 $mu$m and 30 $mu$m. Electrical testing revealed a turn on voltage of approximately 5–6 V, with series resistance dominated post-threshold characteristics. Emission peaks for 10 $mu$m × 10 $mu$m and 30 $mu$m × 30 $mu$m $mu$LEDs were located at 262 nm and 264.5 nm respectively, with emission linewidths of 7.1 nm and 13.6 nm. Power measurements showed light output power densities increasing from 50 mW/cm$^{2}$ at 100 A/cm$^{2}$ to nearly 400 mW/cm$^{2}$ at 800 A/cm$^{2}$. Efficiency droop onset occurred at 83 A/cm$^{2}$ for 30 $mu$m × 30 $mu$m devices and at 200 A/cm$^{2}$ for 10 $mu$m × 10 $mu$m devices. The collective results demonstrate that the AlGaN-delta-GaN QW active region can improve both the IQE and light extraction efficiency of DUV emitting LEDs and could prove to be a viable alternative to conventional designs.
{"title":"Realization of Electrically Driven AlGaN-Delta-GaN QW DUV Micro-LEDs at 265 nm","authors":"Bryan Melanson;Jacob Boisvere;Matthew Seitz;Jing Zhang","doi":"10.1109/JPHOT.2025.3606291","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3606291","url":null,"abstract":"Quantum efficiency of deep-ultraviolet (DUV) light-emitting diodes (LEDs) is a roadblock for these devices to reach efficiencies comparable to their visible light counterparts. The main contributing factor limiting the internal quantum efficiency (IQE) are the effects of the quantum confined Stark effect (QCSE) and valance subband crossover, which can be mitigated through engineering of the quantum well (QW) active region. This work represents the first fabrication and testing of novel full structure electrically driven AlGaN-delta-GaN QW DUV micro-LEDs (<inline-formula><tex-math>$mu$</tex-math></inline-formula>LEDs) with mesa dimensions between 10 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m and 30 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m. Electrical testing revealed a turn on voltage of approximately 5–6 V, with series resistance dominated post-threshold characteristics. Emission peaks for 10 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m × 10 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m and 30 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m × 30 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m <inline-formula><tex-math>$mu$</tex-math></inline-formula>LEDs were located at 262 nm and 264.5 nm respectively, with emission linewidths of 7.1 nm and 13.6 nm. Power measurements showed light output power densities increasing from 50 mW/cm<inline-formula><tex-math>$^{2}$</tex-math></inline-formula> at 100 A/cm<inline-formula><tex-math>$^{2}$</tex-math></inline-formula> to nearly 400 mW/cm<inline-formula><tex-math>$^{2}$</tex-math></inline-formula> at 800 A/cm<inline-formula><tex-math>$^{2}$</tex-math></inline-formula>. Efficiency droop onset occurred at 83 A/cm<inline-formula><tex-math>$^{2}$</tex-math></inline-formula> for 30 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m × 30 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m devices and at 200 A/cm<inline-formula><tex-math>$^{2}$</tex-math></inline-formula> for 10 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m × 10 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m devices. The collective results demonstrate that the AlGaN-delta-GaN QW active region can improve both the IQE and light extraction efficiency of DUV emitting LEDs and could prove to be a viable alternative to conventional designs.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 5","pages":"1-5"},"PeriodicalIF":2.4,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11151212","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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