IEEE Journal of Quantum Electronics最新文献

{"title":"Experimental Demonstration of Quantum Key Distribution Over Deployed Aerial and Underground Multicore Fiber Links","authors":"R. Priyadharshini;Sameer Ahmad Mir;Aswani Ashok;Deepika Rajan;S. Kirubakaran;Hari Krishna Atluri;A. Paventhan;Deepa Venkitesh","doi":"10.1109/JQE.2026.3701984","DOIUrl":"https://doi.org/10.1109/JQE.2026.3701984","url":null,"abstract":"Multicore-fibres (MCF) have emerged as an attractive solution for capacity scaling in optical communication. Securing such links with Quantum Key Distribution (QKD) is critical with the advent of Quantum computers. For practical deployment, QKD is required to operate alongside high-speed classical communication over field-deployed fiber infrastructure. In this work, the performance of QKD is experimentally evaluated in coexistence with high-speed classical data transmission over field-deployed underground and aerial multicore fiber links. The QKD system is implemented with Coherent One-Way Slim protocol, with dedicated Quantum and classical channels for Quantum communication and QKD post-processing. The deployed 4-core MCF infrastructure at IIT Madras provides an effective transmission length of 48 km through loopback operation. QKD performance over the MCF is evaluated in terms of quantum bit error rate (QBER) under varying attenuation, controlled noise injection, and inter-core crosstalk over both singlecore fiber and MCF links. The experimental results show that inter-core crosstalk has a stronger impact in MCF, leading to increased excess noise at the quantum receiver. For a 32-GBaud PM 16-QAM classical modulation format, stable QKD operation is maintained when the spectral separation is approximately six to eight times the occupied bandwidth.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"62 5","pages":"8700408-8700408"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133471","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}

{"title":"Mechanisms Behind Robust and Reliable High-Temperature Current Transport in AlGaN-Based Solar-Blind UV Photodetector","authors":"Balkrishna Choubey;Kankat Ghosh","doi":"10.1109/JQE.2026.3721272","DOIUrl":"https://doi.org/10.1109/JQE.2026.3721272","url":null,"abstract":"In this article, we present the fabrication and detailed characterization of an aluminum gallium nitride-based ultraviolet (UV) solar-blind metal–semiconductor–metal photodetector. We have also demonstrated the carrier transport mechanism of the fabricated device under dark conditions, which supports the thermal stability of the device at high temperatures. The plasma assisted molecular beam epitaxy grown device exhibits high crystalline quality (screw-type threading dislocation density <inline-formula> <tex-math>$= sim 10^{8}$ </tex-math></inline-formula> cm⁻²) and smooth surface morphology (root-mean-square roughness <inline-formula> <tex-math>$= sim 724$ </tex-math></inline-formula> pm), enabling us to fabricate the UV solar-blind photodetector. The fabricated device performs well at room temperature (RT), as it demonstrates low dark current on the order of a few tens of pA (<inline-formula> <tex-math>$6.53times 10^{mathrm {-11}}$ </tex-math></inline-formula>A), high photocurrent (<inline-formula> <tex-math>$3.91times 10^{-6}$ </tex-math></inline-formula> A), high sensitivity (photocurrent-to-dark current ratio <inline-formula> <tex-math>$= sim 10^{5}$ </tex-math></inline-formula>), high responsivity (~13 A/W), high UV-to-visible rejection ratio (<inline-formula> <tex-math>$gt 10^{3}$ </tex-math></inline-formula>), good detectivity (<inline-formula> <tex-math>$sim 10^{11}$ </tex-math></inline-formula> Jones), and fast response time (rise time <inline-formula> <tex-math>$= sim 24~mu $ </tex-math></inline-formula>s and fall time <inline-formula> <tex-math>$= sim 23~mu $ </tex-math></inline-formula>s) at 5 V. The analysis of dark currents at high temperatures (300–475 K) suggests that carriers undergo thermionic emission in the low-field regime (E < 1.67 kV/cm), thermionic field emission in the mid-field regime (1.67 < E < 10 kV/cm), and Poole–Frenkel emission in the high-field regime (E > 10 kV/cm). These mechanisms govern carrier transport and limit the increase in dark current to only two orders of magnitude relative to RT, thereby confirming the stable behaviour of the device at high temperatures. Therefore, the superior RT performance metrics, along with the demonstrated thermal stability under dark conditions at high temperatures, motivate further optimization of the device and its potential commercialization for scientific and industrial applications.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"62 5","pages":"4000208-4000208"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133630","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}

{"title":"Pilot-Assisted and Phase-Modulated Retroreflection for Free-Space Optical Communications","authors":"Matthias F. Jenne;Jonathan F. Holzman","doi":"10.1109/JQE.2026.3721275","DOIUrl":"https://doi.org/10.1109/JQE.2026.3721275","url":null,"abstract":"In this work, we put forward technological solutions for the key challenges in phase-based (coherent and quantum) free-space optical communication (FSOC) systems. We introduce an active transceiver (TRX) terminal for laser transmission and pilot-assisted- (PA-) based reception, and contrast it to the conventional terminal with laser transmission and local-oscillator- (LO-) based reception. From our measurements of error vector magnitude, at received signal powers above –24 dBm, we see that the active PA-TRX terminal can better mitigate turbulence-induced distortion on the propagating signal beam, in contrast to the active LO-TRX terminal. We also introduce a phase-based modulating retroreflector (MRR), in a passive MRR-TRX terminal, that can apply phase modulation onto incident beams (to encode data) and retroreflection (to return the beams to their active terminals with the encoded data). This lets the passive MRR-TRX terminal operate without the payload and complexity of active terminals (having lasers and targeting systems). Our experimental characterizations reveal that the active PA-TRX and passive MRR-TRX terminals can establish effective communication through weak, moderate, and strong turbulence, with received signal powers well above the system’s sensitivity (–30 dBm) and bit-error rates below our limit in the absence of forward error correction (<inline-formula> <tex-math>$10^{-3}$ </tex-math></inline-formula>). Ultimately, we see that the proposed technologies can offer superior performance for emerging phase-based (coherent and quantum) FSOC systems.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"62 5","pages":"8000210-8000210"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133419","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}

{"title":"Influence of Concave Damage and Compensation Structures in Ring-Core Photonic Crystal Fiber on Orbital Angular Momentum Mode Transmission","authors":"Lijuan Zhao;Chengyun Huang;Huanqiu Jiang;Zhiniu Xu","doi":"10.1109/JQE.2026.3707791","DOIUrl":"https://doi.org/10.1109/JQE.2026.3707791","url":null,"abstract":"To address the issue of concave damage in the ring core that occurs during the fabrication of ring-core photonic crystal fiber (PCF), this work investigates its influence on the transmission performance of orbital angular momentum (OAM) modes. Meanwhile, two different compensation structures—adding an inner cladding and thickening the ring core are introduced into the ring-core PCF, and their compensation effects are compared. Simulation based on the COMSOL software platform shows that the concave damage of the ring core reduces the walk-off distance and effective mode field area, but has a slight impact on the mode quality. Analysis within the range of central angle 20°-40° and bending curvature radius 20 -<inline-formula> <tex-math>$60~mu $ </tex-math></inline-formula>m reveals that the thickened ring core structure can maintain high mode quality and increase the effective mode field area, but it exacerbates mode walk-off in high-order modes; in contrast, the inner cladding structure performs well in increasing the walk-off distance yet slightly reduces the mode quality. This work addresses a research gap in the analysis of the effects of ring-core concave damage in PCF research and provides an important reference for the precise fabrication and structural optimization of high-performance optical OAM fibers.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"62 5","pages":"6800608-6800608"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149131875","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}

{"title":"Numerically Studying the Continuous Reflections in Graded-Indexed Waveguide Layer on GaN-Based Fabry–Perot Laser Diodes","authors":"Kangkai Tian;Qiong Zhang;Jianyu Liu;Di Qu;Chunshuang Chu;Yonghui Zhang;Zi-Hui Zhang","doi":"10.1109/JQE.2026.3706977","DOIUrl":"https://doi.org/10.1109/JQE.2026.3706977","url":null,"abstract":"In this work, we establish physical models and propose optically continuous reflections by grading the Al-composition in both n-waveguide and p-waveguide layers (WGLs) for GaN-based Fabry-Perot laser diodes. For the devices with constant-indexed WGLs, only one-time optical reflection occurs at the waveguide layer/cladding layer interface. However, optical reflection always occurs when the light propagates in the graded-indexed WGLs. Hence, such continuous optical reflections more effectively reduce the optical leakage into the passive layers. As a result, an increased optical confinement factor can be achieved, and thus stronger laser power can be obtained. We also find that the Al-composition-graded p-WGL very remarkably affects the electron and hole injections, such that the reduced energy band offset between the p-WGL and p-type electron blocking layer increases the electron leakage level. This sacrifices the electron-hole recombination efficiency in spite of the increased optical confinement factor. This work then makes comprehensive investigations so that the optimized device structure that favors the most improved net modal gain can be obtained.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"62 5","pages":"2000310-2000310"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133516","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}

{"title":"Beyond Three-Octave OAM Supercontinuum Generation in ZBLAN Fiber With Concentric Rings","authors":"Xiaoke Wu;Haoyang Ren;Wenpu Geng;Zhongqi Pan;Yang Yue","doi":"10.1109/JQE.2026.3721282","DOIUrl":"https://doi.org/10.1109/JQE.2026.3721282","url":null,"abstract":"Supercontinuum generation based on orbital angular momentum (OAM) modes offers a pathway toward broadband vortex light sources with expanded functional capabilities. Silica-based optical fibers have been successful in OAM supercontinuum generation; however, the strong absorption limits the application in the mid-infrared (>2500 nm) region. Fluoride glasses, characterized by their wide transmission window, provide an alternative platform for extending OAM supercontinuum spectra toward longer wavelengths. Here, we present a ZBLAN (ZrF₄–BaF₂–LaF₃–AlF₃–NaF) dual-ring-core fiber designed for dispersion-engineered OAM supercontinuum generation. The optimized OAM_1,1 mode exhibits a flat dispersion variation within ±50 ps/(nm<inline-formula> <tex-math>$cdot $ </tex-math></inline-formula>km) over 3830-nm bandwidth from 970 to 4800 nm range, enabling spectral broadening from 1414 nm to 6626 nm under normal-dispersion pumping. Through structural parameter modulation, the OAM_4,1 mode achieves a flatter dispersion response with variation in ±50 ps/(nm<inline-formula> <tex-math>$cdot $ </tex-math></inline-formula>km) between 800 nm and 5200 nm, accompanied by four zero-dispersion wavelengths. Under pulsed excitation, this mode supports a spectrum spanning 592-5240 nm, exceeding three octaves. Further structural refinement extends the OAM_4,1 supercontinuum to 848-6880 nm, corresponding to more than 3 octaves and an additional 1640 nm expansion on the long-wavelength side.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"62 5","pages":"6800712-6800712"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133639","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}

{"title":"Drift–Diffusion-Based Numerical Investigation of Two-Photon Absorption in Broad-Area High-Power Diode Lasers","authors":"Daria Dolinina;Eduard Kuhn;Hans Wenzel","doi":"10.1109/JQE.2026.3723324","DOIUrl":"https://doi.org/10.1109/JQE.2026.3723324","url":null,"abstract":"The effect of two-photon absorption in high-power diode lasers is investigated numerically. The numerical simulation is based on the solution of coupled drift–diffusion and waveguide equations describing a broad-area Fabry–Pérot laser diode. Such an approach allows us to distinguish the direct effect due to inter-band absorption from the indirect effect due to intra-band absorption caused by the generated electron-hole pairs. The influence of two-photon absorption on continuous wave and pulsed laser operation is considered. The phenomenon of a reversed current of minority carriers is demonstrated.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"62 5","pages":"2000408-2000408"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133498","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}

{"title":"Quantum Interference Dynamics in Chip-Scale Photonic Boson Sampling Circuit","authors":"Gaurav Kumar Yadav;Santosh Kumar;Chandan Pathak;Mukesh Kumar","doi":"10.1109/JQE.2026.3695457","DOIUrl":"https://doi.org/10.1109/JQE.2026.3695457","url":null,"abstract":"Boson sampling is a leading platform for exploring many-body quantum interference in linear optical systems. However, identifying circuit-level operating regimes where quantum signatures remain robust under realistic conditions remains challenging. In this work, multimode photonic boson sampling is investigated using a programmable six mode integrated photonic circuit composed of cascaded beam splitters and tunable phase shifters. Each beam splitter is realized through directional couplers combined with local phase control, enabling arbitrary unitary transformations within the linear optical circuit. The circuit is modeled using a tight-binding Hamiltonian allowing controlled manipulation of optical phases and inter-mode coupling that directly governs multiphoton interference pathways. This set up is utilised to do the analysis of Heavy Output Generation (HOG), Total Variation Distance (TVD) and Linear Cross-Entropy Benchmarking (XEB), together with configuration-resolved probability differences, for up to five photons. Distinct dynamic regimes associated with coherent evolution, optimal interference and phase dispersion induced mixing is identified. The results further reveal a photon number dependent complexity–fragility trade-off and demonstrate the robustness of TVD to symmetric photon loss under post-selection. Overall, this work establishes a circuit-relevant validation framework linking programmable interferometer parameters, phase control and quantum interference metrics, providing guidance for scalable photonic boson-sampling implementations in the NISQ regime.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"62 4","pages":"8700308-8700308"},"PeriodicalIF":1.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148747315","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}

{"title":"Data-Driven Machine Learning Analysis of Pulse Compression in Praseodymium-Doped Tapered Photonic-Crystal Fiber","authors":"V. Madhumitha;Faouzi Bahloul;R. Vasantha Jayakantha Raja","doi":"10.1109/JQE.2026.3696524","DOIUrl":"https://doi.org/10.1109/JQE.2026.3696524","url":null,"abstract":"We present a realistic numerical model based on data-driven machine-learning (ML) techniques for generating high-energy ultrashort pulses at <inline-formula> <tex-math>$4.5~mu $ </tex-math></inline-formula>m. To achieve this objective, we propose a nonlinear amplifying loop mirror (NALM) configuration employing a self-similarly designed Praseodymium doped As₂S₃ (Pr³⁺: As₂S₃) tapered photonic crystal fiber (TPCF) compressor, which enables simultaneous pulse amplification and compression. Owing to the increasing complexity of Pr³⁺: As₂S₃ TPCF design, arising from the large parameter space associated with both fiber geometry and pulse characteristics, conventional numerical optimization becomes computationally expensive. Therefore, ML techniques are employed to optimize the TPCF structure and the input pulse parameters. Using the optimized design, we demonstrate that a 5 ps pulse at <inline-formula> <tex-math>$4.5~mu $ </tex-math></inline-formula>m can be compressed to 282.6 fs after propagation through 1.65 m of fiber, corresponding to a maximum compression factor of 17.68, with a pedestal energy of 2.217%.","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"62 4","pages":"6800508-6800508"},"PeriodicalIF":1.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148747657","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}

{"title":"IEEE Journal of Quantum Electronics Information for Authors","authors":"","doi":"10.1109/JQE.2026.3686531","DOIUrl":"https://doi.org/10.1109/JQE.2026.3686531","url":null,"abstract":"","PeriodicalId":13200,"journal":{"name":"IEEE Journal of Quantum Electronics","volume":"62 4","pages":"0001501-0001501"},"PeriodicalIF":1.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11627746","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148628354","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}