A novel scheme for frequency-modulated continuous-wave (FMCW) laser generation, based on electro-optic modulation and sideband injection locking, is proposed and experimentally demonstrated. By exploiting the nonlinear characteristics of a Mach–Zehnder modulator together with the selective amplification enabled by injection locking, the optical carrier energy is efficiently transferred to the positive second-order modulation sideband. As a result, carrier-suppressed single-sideband FMCW modulation with doubled bandwidth is achieved. This bandwidth enhancement significantly improves the range resolution of FMCW LiDAR. Experimental results show that the proposed FMCW laser scheme achieves a wide frequency bandwidth of 6 GHz, a residual nonlinearity as low as $10.3boldsymbol {times } 10{^{text {-5}}}$ , and a fast chirp rate of 2.4 GHz/$upmu $ s. Additionally, the feasibility of LiDAR ranging based on the proposed FMCW laser scheme was demonstrated. The LiDAR system exhibits a range resolution of 2.5 cm, matching the theoretical value. Notably, the proposed scheme eliminates the need for complex modulators, optical filters, and optical amplifiers, while reducing the required electronic bandwidth, thereby facilitating a significant reduction in system cost.
{"title":"Generation of a Frequency-Modulated Continuous-Wave Laser via Sideband Injection Locking for LiDAR","authors":"Renheng Zhang;Kunpeng Zhai;Wenting Wang;Ninghua Zhu","doi":"10.1109/LPT.2025.3645179","DOIUrl":"https://doi.org/10.1109/LPT.2025.3645179","url":null,"abstract":"A novel scheme for frequency-modulated continuous-wave (FMCW) laser generation, based on electro-optic modulation and sideband injection locking, is proposed and experimentally demonstrated. By exploiting the nonlinear characteristics of a Mach–Zehnder modulator together with the selective amplification enabled by injection locking, the optical carrier energy is efficiently transferred to the positive second-order modulation sideband. As a result, carrier-suppressed single-sideband FMCW modulation with doubled bandwidth is achieved. This bandwidth enhancement significantly improves the range resolution of FMCW LiDAR. Experimental results show that the proposed FMCW laser scheme achieves a wide frequency bandwidth of 6 GHz, a residual nonlinearity as low as <inline-formula> <tex-math>$10.3boldsymbol {times } 10{^{text {-5}}}$ </tex-math></inline-formula>, and a fast chirp rate of 2.4 GHz/<inline-formula> <tex-math>$upmu $ </tex-math></inline-formula>s. Additionally, the feasibility of LiDAR ranging based on the proposed FMCW laser scheme was demonstrated. The LiDAR system exhibits a range resolution of 2.5 cm, matching the theoretical value. Notably, the proposed scheme eliminates the need for complex modulators, optical filters, and optical amplifiers, while reducing the required electronic bandwidth, thereby facilitating a significant reduction in system cost.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"38 7","pages":"443-446"},"PeriodicalIF":2.5,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145861206","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}
A method for distributed polarization mode dispersion (PMD) measurement based on machine learning assisted POTDR is presented in this study, which extracts the characteristics of polarization optical time-domain reflectometer (POTDR) curves and inputs them into a pre-trained machine learning model to obtain distributed PMD values. Compared with traditional distributed PMD measurement methods, this proposed method achieves an average local differential group delay (DGD) measurement accuracy of 0.05 ps/km over 50 m, while improving measurement efficiency by 75% compared to methods with similar accuracy, and significantly enhancing the simplicity and efficiency of distributed PMD measurement. The performance of multiple machine learning models for distributed PMD measurement is compared, providing a basis for selecting models for real-time measurement of distributed PMD in optical fiber composite overhead ground wire (OPGW) under different dynamic environments.
{"title":"Distributed PMD Measurement Based on Machine Learning Assisted POTDR","authors":"Xingrui Su;Kaijing Hu;Wei Li;Ming Luo;Weihua Lian;Chen Qiu;JieKui Yu;Yi Jiang;Ran Yan;Yujia Hu","doi":"10.1109/LPT.2025.3645188","DOIUrl":"https://doi.org/10.1109/LPT.2025.3645188","url":null,"abstract":"A method for distributed polarization mode dispersion (PMD) measurement based on machine learning assisted POTDR is presented in this study, which extracts the characteristics of polarization optical time-domain reflectometer (POTDR) curves and inputs them into a pre-trained machine learning model to obtain distributed PMD values. Compared with traditional distributed PMD measurement methods, this proposed method achieves an average local differential group delay (DGD) measurement accuracy of 0.05 ps/km over 50 m, while improving measurement efficiency by 75% compared to methods with similar accuracy, and significantly enhancing the simplicity and efficiency of distributed PMD measurement. The performance of multiple machine learning models for distributed PMD measurement is compared, providing a basis for selecting models for real-time measurement of distributed PMD in optical fiber composite overhead ground wire (OPGW) under different dynamic environments.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"38 6","pages":"418-421"},"PeriodicalIF":2.5,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145830938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-17DOI: 10.1109/LPT.2025.3645230
Yulong Zhao;Shenglin Zeng;Zhijun Sun
Computational spectrometers have strong potentials in miniaturization of spectrometer, and have attracted broad interests. But bottleneck problems still exist in their practical performance, stability, cost and mass production. This work aims on a competitive type of computational spectrometer based on Fabry–Perot (F–P) microcavity array, and proposes methods in facile fabrication of the F–P microcavity array with different thicknesses of cavity media and in–situ characterization of it installed in a spectrometer module to extract preset calibration data for reconstructive measurement of optical spectrum. Fabrication of the F–P microcavity array involves only film deposition and UV photolithography techniques in an elaborately designed multiple–step processing flow. In characterization of the microcavity array, responses of the assembled spectrometer module to monochromatic light at different wavelengths are recorded by an inside image sensor. As–obtained calibration data is supposed to include various system errors and uncertain factors for spectral reconstruction.
{"title":"Fabrication and Characterization of a Fabry–Perot Microcavity Array for Computational Spectrometers","authors":"Yulong Zhao;Shenglin Zeng;Zhijun Sun","doi":"10.1109/LPT.2025.3645230","DOIUrl":"https://doi.org/10.1109/LPT.2025.3645230","url":null,"abstract":"Computational spectrometers have strong potentials in miniaturization of spectrometer, and have attracted broad interests. But bottleneck problems still exist in their practical performance, stability, cost and mass production. This work aims on a competitive type of computational spectrometer based on Fabry–Perot (F–P) microcavity array, and proposes methods in facile fabrication of the F–P microcavity array with different thicknesses of cavity media and in–situ characterization of it installed in a spectrometer module to extract preset calibration data for reconstructive measurement of optical spectrum. Fabrication of the F–P microcavity array involves only film deposition and UV photolithography techniques in an elaborately designed multiple–step processing flow. In characterization of the microcavity array, responses of the assembled spectrometer module to monochromatic light at different wavelengths are recorded by an inside image sensor. As–obtained calibration data is supposed to include various system errors and uncertain factors for spectral reconstruction.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"38 6","pages":"402-405"},"PeriodicalIF":2.5,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-17DOI: 10.1109/LPT.2025.3645227
Feng Xu;Rongqiu Mu;Feixiang Zheng;Zhenyong Dong;Guanghui Wang;Rugang Wang
In this letter, symmetry-broken silicon cuboid tetramer clusters (SSCTC) have been proposed for optical separation of enantiomers, leveraging the enhanced electromagnetic field generated by quasi bound states in the continuum (q-BIC). When the SSCTC is excited at its resonant wavelength with arbitrary polarization, q-BIC will be excited and both the electromagnetic chirality gradient and electromagnetic density will be enhanced. This produces a chiral lateral force on a nanoparticle that is one order of magnitude stronger than non-lateral force, causing the sideways motion of paired enantiomers to exhibit different directions. Our comprehensive simulations demonstrate that the SSCTC will offer high efficiency for chiral particle separation with the consideration of Brownian motion and chiral gradient force. Furthermore, the relationships of separation efficiency and chirality or size of nanoparticles have been investigated. We believe that our research will move forward the techniques of chiral optical tweezers and all-optical enantioseparation in pharmaceutical industries
{"title":"Optical Separation of Enantiomers Using Polarization-Independent Quasi BIC","authors":"Feng Xu;Rongqiu Mu;Feixiang Zheng;Zhenyong Dong;Guanghui Wang;Rugang Wang","doi":"10.1109/LPT.2025.3645227","DOIUrl":"https://doi.org/10.1109/LPT.2025.3645227","url":null,"abstract":"In this letter, symmetry-broken silicon cuboid tetramer clusters (SSCTC) have been proposed for optical separation of enantiomers, leveraging the enhanced electromagnetic field generated by quasi bound states in the continuum (q-BIC). When the SSCTC is excited at its resonant wavelength with arbitrary polarization, q-BIC will be excited and both the electromagnetic chirality gradient and electromagnetic density will be enhanced. This produces a chiral lateral force on a nanoparticle that is one order of magnitude stronger than non-lateral force, causing the sideways motion of paired enantiomers to exhibit different directions. Our comprehensive simulations demonstrate that the SSCTC will offer high efficiency for chiral particle separation with the consideration of Brownian motion and chiral gradient force. Furthermore, the relationships of separation efficiency and chirality or size of nanoparticles have been investigated. We believe that our research will move forward the techniques of chiral optical tweezers and all-optical enantioseparation in pharmaceutical industries","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"38 7","pages":"439-442"},"PeriodicalIF":2.5,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145861211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-17DOI: 10.1109/LPT.2025.3645225
Jiaqi Wang;Hongjia Lin;Zhi Luo;Chao Lu;Tianhua Feng;Zhaohui Li
In this letter, we present a strategy for compact mid-wave infrared (MWIR) spectrometers based on all-dielectric metasurfaces to address the limitations in spectral resolution and footprint. All-dielectric metasurfaces with both electric and magnetic dipole-like resonances are employed to generate distinct broadband transmission spectra, thereby promising high accuracy and resolution for spectral reconstruction. Using only nine metasurfaces of silicon nanowires on a calcium fluoride substrate in combination with compressed sensing and dictionary learning algorithms, the proposed spectrometer achieves a spectral resolution of 10 nm across the 3-$5~mu $ m wavelength range, leading to a large spectral channel density of up to 200, surpassing most reported MWIR computational spectrometers. Furthermore, the reconstruction of the absorption spectra of both carbon dioxide and ethane is successfully demonstrated.
{"title":"Computational Mid-Wave Infrared Spectrometers Based on All-Dielectric Metasurfaces With Dipole Resonances","authors":"Jiaqi Wang;Hongjia Lin;Zhi Luo;Chao Lu;Tianhua Feng;Zhaohui Li","doi":"10.1109/LPT.2025.3645225","DOIUrl":"https://doi.org/10.1109/LPT.2025.3645225","url":null,"abstract":"In this letter, we present a strategy for compact mid-wave infrared (MWIR) spectrometers based on all-dielectric metasurfaces to address the limitations in spectral resolution and footprint. All-dielectric metasurfaces with both electric and magnetic dipole-like resonances are employed to generate distinct broadband transmission spectra, thereby promising high accuracy and resolution for spectral reconstruction. Using only nine metasurfaces of silicon nanowires on a calcium fluoride substrate in combination with compressed sensing and dictionary learning algorithms, the proposed spectrometer achieves a spectral resolution of 10 nm across the 3-<inline-formula> <tex-math>$5~mu $ </tex-math></inline-formula>m wavelength range, leading to a large spectral channel density of up to 200, surpassing most reported MWIR computational spectrometers. Furthermore, the reconstruction of the absorption spectra of both carbon dioxide and ethane is successfully demonstrated.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"38 6","pages":"406-409"},"PeriodicalIF":2.5,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145830930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-17DOI: 10.1109/LPT.2025.3645276
Ran Zhang;Hongping Liu;Yuefei Cai
This letter presents a monolithic integration work that integrates microLEDs ($mu $ LEDs) with a two-transistor-one-capacitor (2T1C) circuitry by selectively overgrowing the LED epi and fabricating 2T1C on a HEMT epi. The 2T1C circuitry consists of two depletion-mode GaN-based high-electron-mobility transistors (HEMTs) and a metal-insulator-metal (MIM) capacitor, all of which are fabricated on the HEMT epi layer. The threshold voltages of the switching HEMT and the driving HEMT are −2.95 V and −3.07 V, respectively, with ON/OFF ratios of $7.17times 10^{4}$ and $6.37times 10^{4}$ . The MIM capacitor, with an area of 0.02 mm2, has a capacitance density of ~1.3 fF/$mu $ m2. The proposed 2T1C circuitry can effectively control the switching state and current levels of the $mu $ LED by applying pulsed input voltages to the switching transistor. The extracted rise and fall times at 100 Hz are $0.34~mu $ s and $2.2~mu $ s, respectively, enabling a fast-switching performance ranging from 120 Hz to 5 kHz. This work paves the way for full GaN-based active-matrix $mu $ LED displays in the near future.
{"title":"Monolithic Integration of μLEDs With GaN-Based 2T1C Circuitry for Active Matrix Microdisplay","authors":"Ran Zhang;Hongping Liu;Yuefei Cai","doi":"10.1109/LPT.2025.3645276","DOIUrl":"https://doi.org/10.1109/LPT.2025.3645276","url":null,"abstract":"This letter presents a monolithic integration work that integrates microLEDs (<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>LEDs) with a two-transistor-one-capacitor (2T1C) circuitry by selectively overgrowing the LED epi and fabricating 2T1C on a HEMT epi. The 2T1C circuitry consists of two depletion-mode GaN-based high-electron-mobility transistors (HEMTs) and a metal-insulator-metal (MIM) capacitor, all of which are fabricated on the HEMT epi layer. The threshold voltages of the switching HEMT and the driving HEMT are −2.95 V and −3.07 V, respectively, with ON/OFF ratios of <inline-formula> <tex-math>$7.17times 10^{4}$ </tex-math></inline-formula> and <inline-formula> <tex-math>$6.37times 10^{4}$ </tex-math></inline-formula>. The MIM capacitor, with an area of 0.02 mm2, has a capacitance density of ~1.3 fF/<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>m2. The proposed 2T1C circuitry can effectively control the switching state and current levels of the <inline-formula> <tex-math>$mu $ </tex-math></inline-formula>LED by applying pulsed input voltages to the switching transistor. The extracted rise and fall times at 100 Hz are <inline-formula> <tex-math>$0.34~mu $ </tex-math></inline-formula>s and <inline-formula> <tex-math>$2.2~mu $ </tex-math></inline-formula>s, respectively, enabling a fast-switching performance ranging from 120 Hz to 5 kHz. This work paves the way for full GaN-based active-matrix <inline-formula> <tex-math>$mu $ </tex-math></inline-formula>LED displays in the near future.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"38 6","pages":"426-429"},"PeriodicalIF":2.5,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145886697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-16DOI: 10.1109/LPT.2025.3645138
Roberta Palmeri;Davide Guarnera;Giuseppe Torrisi;Giorgio S. Mauro;David Mascali;Alberto Bacci;Nunzio Salerno;Santi C. Pavone;Andrea Locatelli;Gino Sorbello
In this letter, we present a physics-assisted design strategy for tapered suspended slot waveguides operating at $2~mu $ m. The proposed methodology enables a precise control of the optical field, specifically tailored for laser-driven dielectric accelerating structures. By using calibration curves that link the silicon waveguide strips width to both the effective refractive index and the accelerating field amplitude, we ensure local phase synchronism along the propagation axis. The design was performed for an input energy of 79 keV, and validated by HFSS simulations as far as the optical field computation is concerned, and by ASTRA-code for the single-particle beam dynamics. The results show an output energy of 102 keV with the optimized structure, corresponding to 20% increase compared to the previous constant-field approach.
{"title":"Physics-Based Optimization of Tapered Suspended Slot Waveguides for Electron Acceleration","authors":"Roberta Palmeri;Davide Guarnera;Giuseppe Torrisi;Giorgio S. Mauro;David Mascali;Alberto Bacci;Nunzio Salerno;Santi C. Pavone;Andrea Locatelli;Gino Sorbello","doi":"10.1109/LPT.2025.3645138","DOIUrl":"https://doi.org/10.1109/LPT.2025.3645138","url":null,"abstract":"In this letter, we present a physics-assisted design strategy for tapered suspended slot waveguides operating at <inline-formula> <tex-math>$2~mu $ </tex-math></inline-formula>m. The proposed methodology enables a precise control of the optical field, specifically tailored for laser-driven dielectric accelerating structures. By using calibration curves that link the silicon waveguide strips width to both the effective refractive index and the accelerating field amplitude, we ensure local phase synchronism along the propagation axis. The design was performed for an input energy of 79 keV, and validated by HFSS simulations as far as the optical field computation is concerned, and by ASTRA-code for the single-particle beam dynamics. The results show an output energy of 102 keV with the optimized structure, corresponding to 20% increase compared to the previous constant-field approach.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"38 7","pages":"475-478"},"PeriodicalIF":2.5,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11301778","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929641","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}
Pub Date : 2025-12-16DOI: 10.1109/LPT.2025.3645070
Khouloud Abdelli
An end-to-end spiking neural architecture is pre sented for real-time, energy-efficient mechanical event detection in optical fibers. The system emulates Short-Time Fourier Transform (STFT) processing using biologically inspired spiking neurons to generate time–frequency spike maps from raw state-of-polarization (SOP) signals. A neuromorphic convolutional network then performs event classification and spectral–temporal localization. Evaluated on experimental SOP data over a 2600 km link, the architecture achieves 97% classification accuracy with over 50,$000times $ lower energy consumption than conventional CNNs, enabling scalable edge inference for sustainable optical sensing.
{"title":"An End-to-End Spiking Architecture for Energy-Efficient Mechanical Event Detection in Optical Fibers","authors":"Khouloud Abdelli","doi":"10.1109/LPT.2025.3645070","DOIUrl":"https://doi.org/10.1109/LPT.2025.3645070","url":null,"abstract":"An end-to-end spiking neural architecture is pre sented for real-time, energy-efficient mechanical event detection in optical fibers. The system emulates Short-Time Fourier Transform (STFT) processing using biologically inspired spiking neurons to generate time–frequency spike maps from raw state-of-polarization (SOP) signals. A neuromorphic convolutional network then performs event classification and spectral–temporal localization. Evaluated on experimental SOP data over a 2600 km link, the architecture achieves 97% classification accuracy with over 50,<inline-formula> <tex-math>$000times $ </tex-math></inline-formula> lower energy consumption than conventional CNNs, enabling scalable edge inference for sustainable optical sensing.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"38 6","pages":"414-417"},"PeriodicalIF":2.5,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145830862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-15DOI: 10.1109/LPT.2025.3644331
Julian L. Pita;Jorge Diego Marconi;Michaël Ménard
Tellurite glasses are of high interest in integrated photonics for sensing and, in particular, telecommunications applications, where they serve as key materials for amplification and mid-IR light sources due to their wide transparent window, thermal and mechanical stability, and high optical nonlinearity. In this work, we present two inverse-designed devices for polarization management on a tellurium dioxide platform: a TM-pass polarizer and a polarization beam splitter. The TM-pass polarizer achieves an average simulated transmission efficiency of −0.6 dB and an polarization crosstalk below −20.9 dB across the entire C-band, with a footprint of only ${mathrm {24~ {mu }text {m}}} times {mathrm {6~ {mu }text {m}}}$ . The polarization beam splitter has an ultra-compact footprint of ${mathrm {28~ {mu }text {m}}} times {mathrm {6~ {mu }text {m}}}$ and achieves average TE${}_{ }$ and TM${}_{ }$ transmission efficiencies of approximately −0.4 dB, with crosstalk below −18.3 dB and −27.2 dB, respectively. These are the first freeform devices demonstrated on a tellurium dioxide platform, exhibiting strong robustness to fabrication variations and showcasing the versatility of the platform beyond nonlinear applications.
{"title":"Inverse-Designed Tellurite Devices for Polarization Control","authors":"Julian L. Pita;Jorge Diego Marconi;Michaël Ménard","doi":"10.1109/LPT.2025.3644331","DOIUrl":"https://doi.org/10.1109/LPT.2025.3644331","url":null,"abstract":"Tellurite glasses are of high interest in integrated photonics for sensing and, in particular, telecommunications applications, where they serve as key materials for amplification and mid-IR light sources due to their wide transparent window, thermal and mechanical stability, and high optical nonlinearity. In this work, we present two inverse-designed devices for polarization management on a tellurium dioxide platform: a TM-pass polarizer and a polarization beam splitter. The TM-pass polarizer achieves an average simulated transmission efficiency of −0.6 dB and an polarization crosstalk below −20.9 dB across the entire C-band, with a footprint of only <inline-formula> <tex-math>${mathrm {24~ {mu }text {m}}} times {mathrm {6~ {mu }text {m}}}$ </tex-math></inline-formula>. The polarization beam splitter has an ultra-compact footprint of <inline-formula> <tex-math>${mathrm {28~ {mu }text {m}}} times {mathrm {6~ {mu }text {m}}}$ </tex-math></inline-formula> and achieves average TE<inline-formula> <tex-math>${}_{ }$ </tex-math></inline-formula> and TM<inline-formula> <tex-math>${}_{ }$ </tex-math></inline-formula> transmission efficiencies of approximately −0.4 dB, with crosstalk below −18.3 dB and −27.2 dB, respectively. These are the first freeform devices demonstrated on a tellurium dioxide platform, exhibiting strong robustness to fabrication variations and showcasing the versatility of the platform beyond nonlinear applications.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"38 6","pages":"422-425"},"PeriodicalIF":2.5,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145830900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-15DOI: 10.1109/LPT.2025.3644433
Liudmila Silanteva;Amado M. Velázquez-Benítez;Eloy Montesinos Garrido;Vincent van Vliet;Menno van den Hout;Marianne Bigot-Astruc;Adrian Amezcua Correa;Pierre Sillard;Frank Achten;Chigo Okonkwo;Thomas Bradley
We focus on experimental mode field diameter (MFD) evolution in tapered single-mode (SMF) and few-mode fibers (FMF) with simulations supporting the trends and including a simulation-only case for a three-core coupled-core fiber (CCF3). Experimental measurements on an FMF supporting ten linearly polarized modes, tapered down to $mathrm {1.84~mu text {m} }$ , show close agreement with simulations and confirm the onset of evanescent mode field expansion. Simulations extended to sub-micrometer diameters predict rapid MFD growth below $approx!{mathrm {2~mu text {m} }}$ for several modes. For CCF3, simulations show supermode evolution into LP-like modes under tapering, with increasing MFD at small waist diameters.
我们重点研究了锥形单模（SMF）和少模光纤（FMF）的实验模场直径（MFD）演变，并进行了支持这一趋势的仿真，其中包括三芯耦合芯光纤（CCF3）的仅仿真案例。在支持十种线极化模式的FMF上的实验测量，逐渐减小到$mathrm {1.84~mu text {m} }$，显示出与模拟的密切一致，并证实了倏逝模场扩展的开始。扩展到亚微米直径的模拟预测了几种模式下MFD在$approx!{mathrm {2~mu text {m} }}$以下的快速增长。对于CCF3，模拟结果表明，随着腰径减小，MFD增加，超模态演化为类lp模态。
{"title":"Measurement of Mode Field Expansion in Tapered Space-Division Multiplexing Fibers","authors":"Liudmila Silanteva;Amado M. Velázquez-Benítez;Eloy Montesinos Garrido;Vincent van Vliet;Menno van den Hout;Marianne Bigot-Astruc;Adrian Amezcua Correa;Pierre Sillard;Frank Achten;Chigo Okonkwo;Thomas Bradley","doi":"10.1109/LPT.2025.3644433","DOIUrl":"https://doi.org/10.1109/LPT.2025.3644433","url":null,"abstract":"We focus on experimental mode field diameter (MFD) evolution in tapered single-mode (SMF) and few-mode fibers (FMF) with simulations supporting the trends and including a simulation-only case for a three-core coupled-core fiber (CCF3). Experimental measurements on an FMF supporting ten linearly polarized modes, tapered down to <inline-formula> <tex-math>$mathrm {1.84~mu text {m} }$ </tex-math></inline-formula>, show close agreement with simulations and confirm the onset of evanescent mode field expansion. Simulations extended to sub-micrometer diameters predict rapid MFD growth below <inline-formula> <tex-math>$approx!{mathrm {2~mu text {m} }}$ </tex-math></inline-formula> for several modes. For CCF3, simulations show supermode evolution into LP-like modes under tapering, with increasing MFD at small waist diameters.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"38 6","pages":"434-437"},"PeriodicalIF":2.5,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145886698","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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