{"title":"Generation of Dual-Frequency Microwave Pulse Based on Active Mode-Locked Optoelectronic Oscillator","authors":"Junfeng Ren;Ping Li;Chenyang Ma;Cheng Gu;Boxiong Cui;Huitong Yang;Zhengyang Xie;Xin Zhao;Zheng Zheng","doi":"10.1109/JPHOT.2025.3578499","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3578499","url":null,"abstract":"Active mode-locked optoelectronic oscillator(AML-OEO) is a high-quality pulsed microwave source that can be used to generate microwave pulse signals in various forms. We introduce a structure for an AML-OEO, which is intended to generate dual- frequency microwave pulses. In the context of a dual-band microwave pulse sequence, each sub-pulse incorporates signals having a pair of distinct center frequencies. Different filters can be selected for adjustment according to the band requirements of different scenarios. The generated dual-band microwave pulse signals exhibit excellent phase noise performance at both carrier frequencies, we can generate pulse signals with phase noise as low as −120.9 dBc/Hz@10 kHz at 6.55 GHz and −120.5 dBc/Hz@10 kHz at 10.79 GHz. This structure is simpler and more compact, and is expected to play a role in multi-band radar, communications and other fields in the future.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 4","pages":"1-6"},"PeriodicalIF":2.1,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11029582","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144519430","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}
{"title":"Mode Optimization and Polarization Control in VCSELs with Sub-Wavelength Gratings","authors":"Yongli Wang;Chuanchuan Li;Yang Zhang;Jian Li;Xin Wei","doi":"10.1109/JPHOT.2025.3578660","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3578660","url":null,"abstract":"We have demonstrated the integration of sub-wavelength gratings (SWG) into a 795 nm vertical cavity surface emitting laser (VCSEL) with inverse surface relief to achieve coordinated control of the mode and polarization. At a grating period of around 0.5 μm and an etching depth range of 60 nm to 100 nm, the reflectivity was higher than 91%. A high reflectivity difference was introduced between different modes, effectively suppressing high-order modes with a side mode suppression ratio (SMSR) of 38 dB. The SWG exhibited different refractive indices for the transverse electric (TE) and transverse magnetic (TM) components, increasing anisotropy and thus enhancing the orthogonal polarization suppression ratio (OPSR) to 26.7 dB. The predesign and relaxed fabrication tolerances of grating parameters may facilitate the mass production of high-performance VCSELs for applications in quantum sensing systems.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 4","pages":"1-6"},"PeriodicalIF":2.1,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11030241","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144597756","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}
{"title":"Dynamic Optical Amplifiers Enable Distributed Equalization in Optical Transmission Systems","authors":"Hongqiang Zou;Da Liu;Kai Zhang","doi":"10.1109/JPHOT.2025.3578614","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3578614","url":null,"abstract":"In this paper, we design and simulated a novel dynamic gain flattening filter (DGFF) module based on polarization-insensitive liquid crystal on silicon (PI-LCoS). The DGFF module measures 26*10.5 mm in size and integrates four DGFFs. Its compact design and minimal optical components reduce costs and enhance manufacturability. In our lab, we built a 6THz C-band transmission system and compared a novel distributed equalization scheme using DGFF in EDFAs with traditional centralized schemes. Results showed that this scheme effectively balanced OSNR across channels, reducing OSNR flatness from 3.5 dB to 0.5 dB. Additionally, it decreased ROADM station attenuation, leading to an average OSNR improvement of about 0.47 dB.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 4","pages":"1-5"},"PeriodicalIF":2.1,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11030253","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144536570","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}
Lorenzo Tunesi;Vittorio Curri;Andrea Carena;Paolo Bardella
{"title":"Enhanced Bandwidth Tunability in Thermally Controlled Multi-Pitch Contra-Directional Couplers","authors":"Lorenzo Tunesi;Vittorio Curri;Andrea Carena;Paolo Bardella","doi":"10.1109/JPHOT.2025.3576041","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3576041","url":null,"abstract":"Grating-Assisted Contra Directional Couplers (GACDCs) are versatile photonic devices which can implement free-spectral-range free add-drop flat-top responses, making them interesting solutions for Wavelength Division Multiplexing (WDM) systems and many other applications requiring spectral shaping. Their bandwidth can be dynamically changed through thermal means, granting an additional degree of freedom in their design and application. Design techniques involving the periodicity of the gratings (pitch chirping) can enhance the effect of this dynamic control, leading to wider bandwidth tunability in terms of both central channel wavelength and passband width, while leaving the control mechanism and power unchanged. In this work, we investigate the limits of these effects, highlighting the advantages through simulation of both the optical response and the thermal control.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 4","pages":"1-11"},"PeriodicalIF":2.1,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11024028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144323195","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}
{"title":"Bandwidth-Variable and Wavelength-Tunable Waveguide Bragg Grating Filter","authors":"Luyao Xie;Lawrence R. Chen","doi":"10.1109/JPHOT.2025.3576075","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3576075","url":null,"abstract":"We propose and demonstrate a waveguide Bragg grating filter that is bandwidth-variable and wavelength-tunable. The filter is implemented using a pair of apodized waveguide Bragg gratings in silicon-on-insulator that are tuned thermally. The bandwidth-variable functionally is achieved by tuning one of the two gratings while holding the other fixed; the corresponding 3 dB bandwidth of the passband can be varied from 2.28 nm to 7.39 nm. For the wavelength tunable filter, the center wavelength can be tuned from 1546.21 nm to 1549.57 nm while maintaining a passband bandwidth of 4.20 nm, or to be tuned from 1556.68 nm to 1562.56 nm while maintaining a passband bandwidth of 2.60 nm. A stopband response can also be wavelength tuned while conserving a 3 dB bandwidth of 5.70 nm. The wavelength tunability is achieved by tuning the two gratings simultaneously.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 4","pages":"1-6"},"PeriodicalIF":2.1,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11021392","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299097","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}
Jiapeng Zhen;Shuai Huang;Silin Guo;Danping Zhang;Kehong Lv;Jing Qiu;Guanjun Liu
{"title":"Mechanism and Verification of Photoelectric Regulation Characteristics of Two-Dimensional Photodetectors","authors":"Jiapeng Zhen;Shuai Huang;Silin Guo;Danping Zhang;Kehong Lv;Jing Qiu;Guanjun Liu","doi":"10.1109/JPHOT.2025.3565277","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3565277","url":null,"abstract":"Two-dimensional photodetectors have an important property that can improve the optical effect by adjusting the Fermi level, and have outstanding development prospects in the field of visible-infrared photoelectric detection. Here, combined with the surface electronic properties of two-dimensional materials, we analyzed the physical mechanism of the photoelectric effect of a photodetector based on two-dimensional materials. By simulating the light waves of different wavelengths induced on the surface of the photodetector, the changes of its conductivity and absorption rate were analyzed. Since the channel material has an electrically tunable Fermi level, the surface electric field will also be regulated with the Fermi level. Finally, we verified its photoelectric performance by preparing a trilayer graphene device. The results show that the light response of the trilayer graphene photodetector reaches the maximum at 1550 nm, and the surface photoelectric electric field distribution is affected by the Fermi level regulation. Our results show that the performance of graphene photodetectors can be efficiently regulated by Fermi level, which provides theoretical support for the performance improvement and material upgrading of photodetectors in the future.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 3","pages":"1-5"},"PeriodicalIF":2.1,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10979879","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937955","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}
{"title":"Polymer Waveguide-Based Crossing Waveguides and Adiabatic-Tapered Directional Couplers for Fiber Compatible Optical Interconnect","authors":"Xiaofeng Liu;Quandong Huang;Bin Xiao;Quankeng Huang;Jiaqi Ran;Zhanxiong Qiu;Shijie Liang;Qingming Chen;Wenchao Jiang;Zhaoqiang Zheng;Xinyong Dong;Sławomir Ertman;Yuwen Qin","doi":"10.1109/JPHOT.2025.3564794","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3564794","url":null,"abstract":"Photonic integrated circuits have intrinsic merits of high integration, large bandwidth, and flexible design, which play an important role in optical communication systems for the interconnect. To increase the integration and routing of photonic circuits for manipulating the guide modes, we propose a simple and effective fiber compatible crossing waveguide to optimize the device layouts. To demonstrate the idea, we fabricated the device through optical lithography, and then optimized the processing parameters based on the analysis of image processing after fabrication, where the fabricated device shows an insertion loss lower than a maximum 1.0 dB with the crossing waveguides perpendicular to each other and operation wavelength from 1450 nm to 1630 nm for the operation of the E<sub>21</sub> and E<sub>11</sub> modes. The device offers the ability to manipulate guide modes without being affected by the waveguide crossing, which can provide a powerful way to form fiber compatible integrated photonic circuits.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 3","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10977837","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073082","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}
{"title":"Photonics Breakthroughs 2024: Advances in Heavy-Metal-Free Quantum Dot Shortwave Infrared Photodetectors and Image Sensors: The Case of Ag2Te QDs","authors":"Yongjie Wang;Gerasimos Konstantatos","doi":"10.1109/JPHOT.2025.3564863","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3564863","url":null,"abstract":"Shortwave infrared (SWIR) light holds promising applications spanning consumer electronics, industrial automation, and biomedical imaging. The detection of shortwave infrared light lays in the centre of SWIR applications. Conventional SWIR detectors rely on epitaxial semiconductors, which are costly and limited by low manufacturing throughput. Colloidal quantum dots (CQDs) have been developed to unravel these issues and comparable device performances have been achieved after decades’ efforts. While CQDs can offer low-cost alternatives once high-volume maturity level is reached, their widespread adoption in consumer electronics market has been hindered also by concerns on the use of lead/mercury-based materials. Recent advances in heavy-metal-free CQDs, such as silver chalcogenides (Ag<sub>2</sub>Te) and III-V semiconductors (InAs, InSb), have demonstrated performance metrics, which, in some cases, rival heavy-metal based counterparts. Progress in synthesis, surface passivation, and device engineering have enabled high detectivity (>10¹² Jones), broad spectral tunability (1000–2000 nm), monolithic integration with silicon readout circuits and proof of concept demonstration in image sensor and LIDAR use cases. These breakthroughs position heavy-metal-free CQDs as an environmentally compliant, scalable solution for next-generation SWIR technologies.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 3","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10977840","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144139962","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}
{"title":"Low-Threshold Broadband Pulse Generation in an All-Fiber Hybrid Mode-Locked Laser","authors":"Tao Che;Zheng Zheng;Xin Zhao","doi":"10.1109/JPHOT.2025.3564789","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3564789","url":null,"abstract":"Mode-locked fiber lasers that can generate femtosecond pulses can find applications in many areas from high-resolution imaging to high-precision measurement. Bandwidth of their output is one of the most important performance parameters. Prior schemes often require more complicated setup or high pump powers, while a simpler laser setup at a lower pump power with a broadband output is more desired. By combining the low-threshold, easily self-starting properties of nonlinear mode-lockers and the pulse-shaping capabilities of the nonlinear polarization rotation effect in the laser, broadband pulses with a 71 nm bandwidth are generated from an all-fiber Erbium fiber laser at a pump power as low as 47.7 mW. Compared to other broadband mode-locked fiber lasers, the pump power requirement is significantly reduced. Our research shows promise in low-cost and power-efficient laser sources for many potential applications.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 3","pages":"1-5"},"PeriodicalIF":2.1,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10978023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943954","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}
{"title":"KEDM: Knowledge-Embedded Diffusion Model for Infrared Image Destriping","authors":"Lingxiao Li;Xin Wang;Dan Huang;Yunan He;Zhuqiang Zhong;Qingling Xia","doi":"10.1109/JPHOT.2025.3564831","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3564831","url":null,"abstract":"Infrared imaging systems are widely used across industries. However, their output images often exhibit striped noise due to the nonuniform response of the detection system, which significantly affects image quality and visual fidelity. To address challenges such as incomplete stripe removal, potential loss of image details and textures, and the generation of artificial artifacts during destriping, we propose a novel stripe removal method based on a knowledge-embedded diffusion model (KEDM). This approach effectively integrates the spatial distribution characteristics of stripe noise with an innovative, data-driven diffusion network model, creating a hybrid knowledge and data-driven framework for stripe correction. The core components of KEDM are the latent diffusion model (LDM) architecture and the directional wavelet convolution module (DWCM). Specifically, LDM leverages a pretrained variational autoencoder (VAE) to transform the input image into latent feature space for efficient diffusion propagation, reducing computational complexity while preserving image restoration quality. Meanwhile, DWCM uses wavelet convolution operations to construct prior loss functions for stripe noise, precisely guiding the diffusion reconstruction process to achieve a clean, stripe-free image. Empirical evaluations on several benchmark datasets demonstrate that the proposed KEDM outperforms other state-of-the-art destriping algorithms in terms of visual quality and quantitative metrics, validating its excellent performance.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 3","pages":"1-9"},"PeriodicalIF":2.1,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10978030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073243","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}