In the fields of biomedical engineering and intelligent sensing, accurate detection of joint flexion angles and directions holds significant application value. A bending angle detection scheme based on the coupling of single-fiber and multi-fiber within a tube is proposed to achieve simultaneous detection of bending angle and direction. The experimental results show that the output optical power of the optical fiber changes with the bending of the tube, and there is still optical output at the bend angle of 180°. Additionally, the output optical power of the output fiber is correlated with the bending direction, with lower optical loss observed for the output fiber located at the -x direction of the fiber core center. Therefore, the bending direction of the tube can be determined by comparing the output optical loss between fibers. On the other hand, the bending angle can be obtained from the total loss of all output fibers. Experimental results indicate that the sensor possesses high sensitivity of up to 0.181dB/° for the angle range from 0° to 180°, and a linear regression coefficient R2 of 0.993. Additionally, experiments conducted with motors and finger joints have demonstrated the excellent reversibility and rapid response capabilities of the proposed angular sensor, thereby indicating its potential as an effective solution for precise monitoring of joint movements.
{"title":"Research on high-sensitivity joint bending angle and direction detection sensor based on multi-fiber end-face coupling","authors":"Chong Zhu, Ting Zhou, Zhi-Bin Wang, Ming-Yang Chen","doi":"10.1016/j.optcom.2025.131738","DOIUrl":"10.1016/j.optcom.2025.131738","url":null,"abstract":"<div><div>In the fields of biomedical engineering and intelligent sensing, accurate detection of joint flexion angles and directions holds significant application value. A bending angle detection scheme based on the coupling of single-fiber and multi-fiber within a tube is proposed to achieve simultaneous detection of bending angle and direction. The experimental results show that the output optical power of the optical fiber changes with the bending of the tube, and there is still optical output at the bend angle of 180°. Additionally, the output optical power of the output fiber is correlated with the bending direction, with lower optical loss observed for the output fiber located at the -x direction of the fiber core center. Therefore, the bending direction of the tube can be determined by comparing the output optical loss between fibers. On the other hand, the bending angle can be obtained from the total loss of all output fibers. Experimental results indicate that the sensor possesses high sensitivity of up to 0.181dB/° for the angle range from 0° to 180°, and a linear regression coefficient R<sup>2</sup> of 0.993. Additionally, experiments conducted with motors and finger joints have demonstrated the excellent reversibility and rapid response capabilities of the proposed angular sensor, thereby indicating its potential as an effective solution for precise monitoring of joint movements.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"583 ","pages":"Article 131738"},"PeriodicalIF":2.2,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
On-chip silicon polarizers with broad operating bandwidth and compact footprint have recently attracted increasing attention for their applications in large capacity and high density integrated optical systems. In this paper, we present, to the best of our knowledge, the highest bandwidth TM-pass polarizer based on hybrid plasmonic waveguides engineered with subwavelength gratings. The device's bandwidth spans all ITU-defined optical communication bands. Additionally, by flexibly adjusting the device parameters, the operating bandwidth can be extended into the 2 μm mid-infrared (MIR) region. The use of a rib waveguide structure on a silicon-on-insulator wafer with a thicker silicon device layer enables significant spatial differences between the TE and TM mode field distributions. In regions where the TE mode dominates, Cr metal with high absorption loss is strategically placed, enabling low-loss transmission for the TM mode while rapidly attenuating the TE mode. To validate the design concept, we developed two device configurations with different lengths of 8 μm and 12 μm. Numerical results indicate that for the 8 μm design, the device achieves an operating bandwidth of 748 nm (1148 nm–1896 nm) with an insertion loss (IL) < 1 dB and a polarization extinction ratio (PER) > 20 dB. If the IL requirement is relaxed to 2 dB while maintaining a PER above 20 dB, the operating bandwidth extends to 1189 nm (1141 nm–2330 nm). For the 12 μm design, the device achieves an operating bandwidth of 620 nm (1148 nm–1768 nm) with IL < 1 dB and PER >20 dB. With IL < 3 dB and PER >20 dB, the operating bandwidth reaches 1209 nm (1141 nm–2350 nm). Additionally, we optimized the waveguide structure parameters to design a low-loss configuration around the 2 μm band. This work offers a new approach for creating compact, ultra-broadband on-chip polarizers with potential applications in high-capacity, high-density optical interconnects and optical communication systems.
{"title":"Compact on-chip silicon TM polarizer with ultra-wide bandwidth covering all ITU optical communication bands up to the 2 μm mid-infrared","authors":"Chen Zhang , Panlai Li , Wenya Guo , Ting Feng , Xiaofei Gu , Shengbao Wu","doi":"10.1016/j.optcom.2025.131737","DOIUrl":"10.1016/j.optcom.2025.131737","url":null,"abstract":"<div><div>On-chip silicon polarizers with broad operating bandwidth and compact footprint have recently attracted increasing attention for their applications in large capacity and high density integrated optical systems. In this paper, we present, to the best of our knowledge, the highest bandwidth TM-pass polarizer based on hybrid plasmonic waveguides engineered with subwavelength gratings. The device's bandwidth spans all ITU-defined optical communication bands. Additionally, by flexibly adjusting the device parameters, the operating bandwidth can be extended into the 2 μm mid-infrared (MIR) region. The use of a rib waveguide structure on a silicon-on-insulator wafer with a thicker silicon device layer enables significant spatial differences between the TE and TM mode field distributions. In regions where the TE mode dominates, Cr metal with high absorption loss is strategically placed, enabling low-loss transmission for the TM mode while rapidly attenuating the TE mode. To validate the design concept, we developed two device configurations with different lengths of 8 μm and 12 μm. Numerical results indicate that for the 8 μm design, the device achieves an operating bandwidth of 748 nm (1148 nm–1896 nm) with an insertion loss (IL) < 1 dB and a polarization extinction ratio (PER) > 20 dB. If the IL requirement is relaxed to 2 dB while maintaining a PER above 20 dB, the operating bandwidth extends to 1189 nm (1141 nm–2330 nm). For the 12 μm design, the device achieves an operating bandwidth of 620 nm (1148 nm–1768 nm) with IL < 1 dB and PER >20 dB. With IL < 3 dB and PER >20 dB, the operating bandwidth reaches 1209 nm (1141 nm–2350 nm). Additionally, we optimized the waveguide structure parameters to design a low-loss configuration around the 2 μm band. This work offers a new approach for creating compact, ultra-broadband on-chip polarizers with potential applications in high-capacity, high-density optical interconnects and optical communication systems.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"583 ","pages":"Article 131737"},"PeriodicalIF":2.2,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-08DOI: 10.1016/j.optcom.2025.131736
Shundong Qu , Yanzhong Chen , Zecheng Lei , Yaodong Qi , Feng Yuan , Jisi Qiu , Hao Liu , Haocheng Wang , Tianli Yang , Xue Zhang , Zhongwei Fan
The parasitic oscillations in an end-pumped zigzag slab laser are analyzed. The specific geometric route of the parasitic oscillation observed in experiment is deduced in detail for the first time. A numerical analysis of the gain and loss along the parasitic oscillations route is performed, and the critical condition of parasitic oscillations is calculated. The coating technology is employed to increase the losses along the parasitic oscillations route to suppress parasitic oscillations. The maximum output power of a short resonant cavity of the slab module and the maximum small signal gain of the slab amplifier increase by 21.4% and 17.4% after the suppression of parasitic oscillations, respectively.
{"title":"Geometric route solving of the observed parasitic oscillation and analysis of parasitic oscillation suppression in an end-pumped zigzag slab laser","authors":"Shundong Qu , Yanzhong Chen , Zecheng Lei , Yaodong Qi , Feng Yuan , Jisi Qiu , Hao Liu , Haocheng Wang , Tianli Yang , Xue Zhang , Zhongwei Fan","doi":"10.1016/j.optcom.2025.131736","DOIUrl":"10.1016/j.optcom.2025.131736","url":null,"abstract":"<div><div>The parasitic oscillations in an end-pumped zigzag slab laser are analyzed. The specific geometric route of the parasitic oscillation observed in experiment is deduced in detail for the first time. A numerical analysis of the gain and loss along the parasitic oscillations route is performed, and the critical condition of parasitic oscillations is calculated. The coating technology is employed to increase the losses along the parasitic oscillations route to suppress parasitic oscillations. The maximum output power of a short resonant cavity of the slab module and the maximum small signal gain of the slab amplifier increase by 21.4% and 17.4% after the suppression of parasitic oscillations, respectively.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"583 ","pages":"Article 131736"},"PeriodicalIF":2.2,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-07DOI: 10.1016/j.optcom.2025.131734
Yifan Chen , Fan Li , Jianjun Yu
We investigate the advantages and challenges associated with the implementation of trellis-coded modulation 16-ary quadrature amplitude modulation (TCM-16QAM) in optical fiber transmissions. Despite the potential benefits of enhanced sensitivity and spectral efficiency with TCM-QAM, fiber nonlinearity can compromise its performance at higher launch powers into optical fibers. This is mainly attributed to nonlinear noise and inter-symbol interference exacerbating burst errors post-Viterbi decoding. To address this challenge, we propose a low-complexity symbol-level block interleaving technique based on a simple transpose operation. This method disperses consecutive erroneous symbols into isolated ones, thereby reducing burst errors output from the Viterbi decoder. We first validate the proposed symbol-level method through simulations of polarization-division multiplexed (PDM) signals over 12 × 80-km standard single-mode fiber (SSMF). TCM-16QAM with interleaving depths of 2, 4, and 16 achieves a coding gain of 0.76–1.08 dB at a bit error rate (BER) of 1 × 10−3, while the launch power tolerance increases from 1.39 to 1.97 dB in the nonlinear transmission region compared to conventional 8 phase shift keying (8PSK) modulation with the same spectral efficiency. Furthermore, we perform experimental transmissions employing 32-GBaud PDM signals over 3 × 80-km SSMF. The experimental results reveal that in the nonlinear transmission region, TCM-16QAM with interleaving depths of 4 and 16 can achieve the launch power tolerance improvements of 0.48 dB and 0.67 dB, respectively.
{"title":"TCM-16QAM in nonlinear fiber transmissions","authors":"Yifan Chen , Fan Li , Jianjun Yu","doi":"10.1016/j.optcom.2025.131734","DOIUrl":"10.1016/j.optcom.2025.131734","url":null,"abstract":"<div><div>We investigate the advantages and challenges associated with the implementation of trellis-coded modulation 16-ary quadrature amplitude modulation (TCM-16QAM) in optical fiber transmissions. Despite the potential benefits of enhanced sensitivity and spectral efficiency with TCM-QAM, fiber nonlinearity can compromise its performance at higher launch powers into optical fibers. This is mainly attributed to nonlinear noise and inter-symbol interference exacerbating burst errors post-Viterbi decoding. To address this challenge, we propose a low-complexity symbol-level block interleaving technique based on a simple transpose operation. This method disperses consecutive erroneous symbols into isolated ones, thereby reducing burst errors output from the Viterbi decoder. We first validate the proposed symbol-level method through simulations of polarization-division multiplexed (PDM) signals over 12 × 80-km standard single-mode fiber (SSMF). TCM-16QAM with interleaving depths of 2, 4, and 16 achieves a coding gain of 0.76–1.08 dB at a bit error rate (BER) of 1 × 10<sup>−3</sup>, while the launch power tolerance increases from 1.39 to 1.97 dB in the nonlinear transmission region compared to conventional 8 phase shift keying (8PSK) modulation with the same spectral efficiency. Furthermore, we perform experimental transmissions employing 32-GBaud PDM signals over 3 × 80-km SSMF. The experimental results reveal that in the nonlinear transmission region, TCM-16QAM with interleaving depths of 4 and 16 can achieve the launch power tolerance improvements of 0.48 dB and 0.67 dB, respectively.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"583 ","pages":"Article 131734"},"PeriodicalIF":2.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-07DOI: 10.1016/j.optcom.2025.131733
Gang Zhang , Shuhan Wang , Xinyu Wang , Jianhui Zhu , Linguang Xu , Qiang Ge
Ellipse fitting algorithms (EFAs) utilizing the traditional least squares method (LSM) are not robust in nonlinear systems and even fail when the input elliptic arc is short. To address the challenges, we propose a high-fidelity phase generated carrier (PGC) demodulation algorithm integrating the arctangent method, an extended Kalman filter (EKF) and a combined modulation. The EKF derives optimal state estimation from the nonlinear system by linearizing nonlinear functions, resulting in high accuracy in ellipse fitting. The laser undergoes internal modulation via a combination of low and high frequencies, which not only generates a phase carrier but also induces a large low frequency phase shift in the interferometric sensors. This shift guarantees the Lissajous arc length, thereby preventing fitting failures. The experimental results demonstrate that the EFA employing EKF is consistently superior to that utilizing LSM by comparing the eccentricities of the corrected Lissajous figures. Notably, the proposed algorithm has never failed due to the presence of the low frequency modulation. The average signal-to-noise-and-distortion of the demodulated signal of the proposed algorithm is 62.04 dB in the carrier modulation depth range of 1.5–3.0 rad, which is 46.79 dB higher than that of the PGC-LSM-Arctan demodulation algorithm. The proposed algorithm has promising application prospects in fiber optic sensors as it can effectively eliminate the nonlinear errors and has high robustness.
{"title":"A high-fidelity PGC-Arctan demodulation algorithm employing an extended Kalman filter and a combined modulation","authors":"Gang Zhang , Shuhan Wang , Xinyu Wang , Jianhui Zhu , Linguang Xu , Qiang Ge","doi":"10.1016/j.optcom.2025.131733","DOIUrl":"10.1016/j.optcom.2025.131733","url":null,"abstract":"<div><div>Ellipse fitting algorithms (EFAs) utilizing the traditional least squares method (LSM) are not robust in nonlinear systems and even fail when the input elliptic arc is short. To address the challenges, we propose a high-fidelity phase generated carrier (PGC) demodulation algorithm integrating the arctangent method, an extended Kalman filter (EKF) and a combined modulation. The EKF derives optimal state estimation from the nonlinear system by linearizing nonlinear functions, resulting in high accuracy in ellipse fitting. The laser undergoes internal modulation via a combination of low and high frequencies, which not only generates a phase carrier but also induces a large low frequency phase shift in the interferometric sensors. This shift guarantees the Lissajous arc length, thereby preventing fitting failures. The experimental results demonstrate that the EFA employing EKF is consistently superior to that utilizing LSM by comparing the eccentricities of the corrected Lissajous figures. Notably, the proposed algorithm has never failed due to the presence of the low frequency modulation. The average signal-to-noise-and-distortion of the demodulated signal of the proposed algorithm is 62.04 dB in the carrier modulation depth range of 1.5–3.0 rad, which is 46.79 dB higher than that of the PGC-LSM-Arctan demodulation algorithm. The proposed algorithm has promising application prospects in fiber optic sensors as it can effectively eliminate the nonlinear errors and has high robustness.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"583 ","pages":"Article 131733"},"PeriodicalIF":2.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-07DOI: 10.1016/j.optcom.2025.131730
Jie Xu , Yannick Guyot , Jian Liu , Xiaodong Xu , Jun Xu , Kheirreddine Lebbou , Richard Moncorgé
Trivalent rare-earth (RE) ion-doped Bi4Ge3O12 (BGO) crystals exhibit exceptional potentialities for laser applications owing to their favorable emission characteristics, superior optical/thermo-mechanical properties, and non-hygroscopic nature. This review systematically summarizes recent progresses in the growth techniques and luminescence properties of RE3+ (Nd3+, Er3+, Tm3+, Ho3+, Pr3+)-doped BGO crystals. We critically analyze four dominant growth techniquess, such as Czochralski, Micro-pulling-down (μ-PD), Floating zone, and Bridgman-Stockbarger, thus highlighting their suitability for achieving high-quality single crystals. Detailed spectroscopic investigations reveal that Nd3+-doped BGO leads to efficient continuous-wave lasing at 1064 nm, while Pr3+ and Er3+ co-dopings enable multi-wavelength emissions spanning visible to mid-infrared regions. Challenges in suppressing non-radiative transitions and optimizing dopant concentrations for laser performance are discussed, providing a roadmap for future research in advanced optoelectronic devices.
{"title":"Rare-earth doped Bi4Ge3O12 crystals: Advances in growth techniques and luminescence properties for laser applications","authors":"Jie Xu , Yannick Guyot , Jian Liu , Xiaodong Xu , Jun Xu , Kheirreddine Lebbou , Richard Moncorgé","doi":"10.1016/j.optcom.2025.131730","DOIUrl":"10.1016/j.optcom.2025.131730","url":null,"abstract":"<div><div>Trivalent rare-earth (RE) ion-doped Bi<sub>4</sub>Ge<sub>3</sub>O<sub>12</sub> (BGO) crystals exhibit exceptional potentialities for laser applications owing to their favorable emission characteristics, superior optical/thermo-mechanical properties, and non-hygroscopic nature. This review systematically summarizes recent progresses in the growth techniques and luminescence properties of RE<sup>3+</sup> (Nd<sup>3+</sup>, Er<sup>3+</sup>, Tm<sup>3+</sup>, Ho<sup>3+</sup>, Pr<sup>3+</sup>)-doped BGO crystals. We critically analyze four dominant growth techniquess, such as Czochralski, Micro-pulling-down (μ-PD), Floating zone, and Bridgman-Stockbarger, thus highlighting their suitability for achieving high-quality single crystals. Detailed spectroscopic investigations reveal that Nd<sup>3+</sup>-doped BGO leads to efficient continuous-wave lasing at 1064 nm, while Pr<sup>3+</sup> and Er<sup>3+</sup> co-dopings enable multi-wavelength emissions spanning visible to mid-infrared regions. Challenges in suppressing non-radiative transitions and optimizing dopant concentrations for laser performance are discussed, providing a roadmap for future research in advanced optoelectronic devices.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"583 ","pages":"Article 131730"},"PeriodicalIF":2.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-07DOI: 10.1016/j.optcom.2025.131715
Mingqian Zhou, Haole Kong, Zhiming Zhang, Yanghui Li, Juan Kang, Lu Yin, Yi Li, Le Wang
We present a new spectrometer design which combines a conventional prism spectrometer with planar lightwave circuits (PLC) in this study. The PLC chip was integrated in front of the prism as a scattering medium to improve the spectral resolution. Interferences among different modes in the multimode waveguide create wavelength-dependent speckle patterns. Since the speckle patterns corresponding to different wavelengths are deterministic and unique, they can be utilized for wavelength identification after calibration. In addition, the spectral-spatial mapping through the prism further enhances the contrast of speckles, thereby improving the resolution and bandwidth. Compared with conventional prism spectrometers, the speckle-enhanced prism spectrometer incorporates both a scattering medium and a prism, enabling simultaneous high resolution and wide bandwidth. Moreover, the narrow output of the PLC can replace the slit in conventional spectrometers, further improving the optical efficiency to 40%. In demonstration experiments, the proposed spectrometer successfully measured multiple laser wavelengths and a broad band light source. The resolution of up to 5 pm over the wavelength range of 1525–1565 nm was achieved. This study paves the way for the development of high-resolution spectrometers with smaller volumes and higher optical efficiency.
{"title":"A speckle enhanced prism spectrometer based on planar lightwave circuit chip","authors":"Mingqian Zhou, Haole Kong, Zhiming Zhang, Yanghui Li, Juan Kang, Lu Yin, Yi Li, Le Wang","doi":"10.1016/j.optcom.2025.131715","DOIUrl":"10.1016/j.optcom.2025.131715","url":null,"abstract":"<div><div>We present a new spectrometer design which combines a conventional prism spectrometer with planar lightwave circuits (PLC) in this study. The PLC chip was integrated in front of the prism as a scattering medium to improve the spectral resolution. Interferences among different modes in the multimode waveguide create wavelength-dependent speckle patterns. Since the speckle patterns corresponding to different wavelengths are deterministic and unique, they can be utilized for wavelength identification after calibration. In addition, the spectral-spatial mapping through the prism further enhances the contrast of speckles, thereby improving the resolution and bandwidth. Compared with conventional prism spectrometers, the speckle-enhanced prism spectrometer incorporates both a scattering medium and a prism, enabling simultaneous high resolution and wide bandwidth. Moreover, the narrow output of the PLC can replace the slit in conventional spectrometers, further improving the optical efficiency to 40%. In demonstration experiments, the proposed spectrometer successfully measured multiple laser wavelengths and a broad band light source. The resolution of up to 5 pm over the wavelength range of 1525–1565 nm was achieved. This study paves the way for the development of high-resolution spectrometers with smaller volumes and higher optical efficiency.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"583 ","pages":"Article 131715"},"PeriodicalIF":2.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-07DOI: 10.1016/j.optcom.2025.131731
Changhui Liu, Changjun Xu, Juan Wang, Zhe Huang, Shunbin Wang, Pengfei Wang
Fibres are significant propagating and gain medium, drawing wide attention and rapid developments in the past several decades. Among them, fluoride fibres achieve a big success in the applications of lasers and amplifiers at the near-infrared and mid-infrared areas due to the advantages of the broad transmission window, low phonon energy and high doping concentration. Particularly, fibre amplifiers are indispensable devices for enhancing signal strength in optical communication and other light transfer systems. This paper provides a systematic overview of the fluoride fibre material properties, fabrication techniques, and technological advancements, alongside a comprehensive review of current research on fluoride fibre amplifiers within the near-infrared and mid-infrared domains. Furthermore, by comparing fluoride and silica fibre amplifiers, this study offers a detailed analysis of the advantages and technical challenges posed by fluoride fibre amplifiers, providing insights for improving their performance and broadening their application scope.
{"title":"Fluoride fibres amplifiers","authors":"Changhui Liu, Changjun Xu, Juan Wang, Zhe Huang, Shunbin Wang, Pengfei Wang","doi":"10.1016/j.optcom.2025.131731","DOIUrl":"10.1016/j.optcom.2025.131731","url":null,"abstract":"<div><div>Fibres are significant propagating and gain medium, drawing wide attention and rapid developments in the past several decades. Among them, fluoride fibres achieve a big success in the applications of lasers and amplifiers at the near-infrared and mid-infrared areas due to the advantages of the broad transmission window, low phonon energy and high doping concentration. Particularly, fibre amplifiers are indispensable devices for enhancing signal strength in optical communication and other light transfer systems. This paper provides a systematic overview of the fluoride fibre material properties, fabrication techniques, and technological advancements, alongside a comprehensive review of current research on fluoride fibre amplifiers within the near-infrared and mid-infrared domains. Furthermore, by comparing fluoride and silica fibre amplifiers, this study offers a detailed analysis of the advantages and technical challenges posed by fluoride fibre amplifiers, providing insights for improving their performance and broadening their application scope.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"583 ","pages":"Article 131731"},"PeriodicalIF":2.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-07DOI: 10.1016/j.optcom.2025.131735
Shuxin Ma, Chonglei Zhang
In optical imaging, phase information of light waves is critical for object recognition. The phase retrieval problem can be reformulated as an optimization problem by utilizing the Extended Nijboer-Zernike theory (ENZ). To address the issues of slow convergence and large residuals in solving Zernike polynomials using the classical quasi-Newton method, this study proposes the implementation of the momentum and Adam methods. Through comparative experiments, it was demonstrated that the momentum and Adam methods can effectively enhance convergence speed, reduce final residuals, and achieve superior convergence results compared to the quasi-Newton method. Furthermore, the momentum method was observed to approximate the optimal solution more closely than the Adam method did. This study presents improved methods for applying ENZ in phase retrieval, potentially enhancing the precision and efficiency of optical imaging techniques.
{"title":"Comparison of different phase retrieval algorithms based on ENZ theory","authors":"Shuxin Ma, Chonglei Zhang","doi":"10.1016/j.optcom.2025.131735","DOIUrl":"10.1016/j.optcom.2025.131735","url":null,"abstract":"<div><div>In optical imaging, phase information of light waves is critical for object recognition. The phase retrieval problem can be reformulated as an optimization problem by utilizing the Extended Nijboer-Zernike theory (ENZ). To address the issues of slow convergence and large residuals in solving Zernike polynomials using the classical quasi-Newton method, this study proposes the implementation of the momentum and Adam methods. Through comparative experiments, it was demonstrated that the momentum and Adam methods can effectively enhance convergence speed, reduce final residuals, and achieve superior convergence results compared to the quasi-Newton method. Furthermore, the momentum method was observed to approximate the optimal solution more closely than the Adam method did. This study presents improved methods for applying ENZ in phase retrieval, potentially enhancing the precision and efficiency of optical imaging techniques.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"583 ","pages":"Article 131735"},"PeriodicalIF":2.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-07DOI: 10.1016/j.optcom.2025.131716
Ying Zhao , Xiaodan Fan , Meigang Duan , Yao Ju , Xin Deng , Zuogang Yang , Haolan Huangfu , Xiaozhan Yang , Jie Hu , Haoyi Zuo
This paper reports a method of manipulating scattered light fields based on third-order correlation of light fields (TCLF) guided by a mask. Different from the traditional computational reconstruction of object images through the second-order correlation of light intensity in ghost imaging, the TCLF can optically reconstruct mask images in scattered fields. This optical reconstruction process enables a portion of the energy in the scattered field to be redistributed to match the object, thus enabling this imaging technique to serve as scattering wavefront shaping (SWFS) guided by a mask. Experiments show that the TCLF can easily achieve SWFS with high-resolution modulation, which has always been a challenge in this research field. With high-resolution modulation, the TCLF can shape the scattered field into more complex images, including grayscale images, and even enable video transmission through the scattering medium. This research provides a new and powerful method for SWFS, thus offering technical support for scattering-assisted holography and finding potential applications in complex media imaging in the future.
{"title":"Scattering wavefront shaping guided by mask based on third-order correlation of light fields","authors":"Ying Zhao , Xiaodan Fan , Meigang Duan , Yao Ju , Xin Deng , Zuogang Yang , Haolan Huangfu , Xiaozhan Yang , Jie Hu , Haoyi Zuo","doi":"10.1016/j.optcom.2025.131716","DOIUrl":"10.1016/j.optcom.2025.131716","url":null,"abstract":"<div><div>This paper reports a method of manipulating scattered light fields based on third-order correlation of light fields (TCLF) guided by a mask. Different from the traditional computational reconstruction of object images through the second-order correlation of light intensity in ghost imaging, the TCLF can optically reconstruct mask images in scattered fields. This optical reconstruction process enables a portion of the energy in the scattered field to be redistributed to match the object, thus enabling this imaging technique to serve as scattering wavefront shaping (SWFS) guided by a mask. Experiments show that the TCLF can easily achieve SWFS with high-resolution modulation, which has always been a challenge in this research field. With high-resolution modulation, the TCLF can shape the scattered field into more complex images, including grayscale images, and even enable video transmission through the scattering medium. This research provides a new and powerful method for SWFS, thus offering technical support for scattering-assisted holography and finding potential applications in complex media imaging in the future.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"583 ","pages":"Article 131716"},"PeriodicalIF":2.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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