Pub Date : 2026-01-22DOI: 10.1016/j.optcom.2026.132948
Xiaoqin Bai , Min Han , Rongcao Yang
In this work, we present a versatile method for achieving unidirectional and bidirectional soliton conversion, together with controllable oscillation and helical rotation of solitons by introducing longitudinally alternating inhomogeneous potentials into fractional diffraction system. Across diverse alternating potentials, the soliton undergoes unidirectional conversion into distinct and tailored states, including periodic and Hermite-Gaussian solitons, with the conversion efficiency jointly governed by Lévy index and potential parameters. Under the selected longitudinal inhomogeneous modulation, judiciously engineering the alternating second potential drives bidirectional conversion of diverse solitons—ring and necklace solitons among them. Additionally, the controlled oscillation and helical rotation of soliton pairs in alternating inhomogeneous fractional diffraction system are examined in detail. The study enriches the research of potential engineering in fractional diffraction systems, and holds promise for revealing novel physical phenomena—driven by the interplay of fractional Lévy index and dynamic potentials—that may be difficult to be observed in conventional integer-order diffraction systems. In addition, the steerable soliton conversion, oscillation and helical rotation open an excellent prospect for optical switching, optical modulation and other related technologies.
{"title":"Conversion, oscillation and helical rotation of solitons in alternating inhomogeneous fractional diffraction system","authors":"Xiaoqin Bai , Min Han , Rongcao Yang","doi":"10.1016/j.optcom.2026.132948","DOIUrl":"10.1016/j.optcom.2026.132948","url":null,"abstract":"<div><div>In this work, we present a versatile method for achieving unidirectional and bidirectional soliton conversion, together with controllable oscillation and helical rotation of solitons by introducing longitudinally alternating inhomogeneous potentials into fractional diffraction system. Across diverse alternating potentials, the soliton undergoes unidirectional conversion into distinct and tailored states, including periodic and Hermite-Gaussian solitons, with the conversion efficiency jointly governed by Lévy index and potential parameters. Under the selected longitudinal inhomogeneous modulation, judiciously engineering the alternating second potential drives bidirectional conversion of diverse solitons—ring and necklace solitons among them. Additionally, the controlled oscillation and helical rotation of soliton pairs in alternating inhomogeneous fractional diffraction system are examined in detail. The study enriches the research of potential engineering in fractional diffraction systems, and holds promise for revealing novel physical phenomena—driven by the interplay of fractional Lévy index and dynamic potentials—that may be difficult to be observed in conventional integer-order diffraction systems. In addition, the steerable soliton conversion, oscillation and helical rotation open an excellent prospect for optical switching, optical modulation and other related technologies.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132948"},"PeriodicalIF":2.5,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080060","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 : 2026-01-22DOI: 10.1016/j.optcom.2026.132922
Ajun Shao , Shuting Ma , Xingyu Zhang , Zhuang Zhao , Baohui Guo , Mingze Ma , Jing Han , Yong Peng , Yi Zhang , Lianfa Bai , Guohua Gu , Xin Liu
Near-infrared hyperspectral images (NIR-HSIs, 900–1700 nm) offer rich spectral information and strong haze-penetrating capability, but their performance is often constrained by sensor noise, leading to low signal-to-noise ratio (SNR), diminished contrast, and texture degradation. In contrast, RGB cameras offer higher SNR and richer texture details while being low-cost and widely accessible, thus serving as effective priors to enhance reconstruction of NIR-HSI. This paper propose an RGB-Guided Phase-Aware Hybrid Prior (RGB-PAHP) method within a dual-camera system, where an RGB camera is integrated into a coded aperture snapshot spectral imaging (CASSI) architecture. A multi-scale RGB feature extraction module (RGB-FE) is designed to fully exploit spatial details from RGB images, effectively guiding the reconstruction of NIR-HSI with high SNR. Furthermore, the method employs a deep unfolding network entirely based on multilayer perceptron (MLP), and introduces a Degradation-Aware Residual Gradient Descent (DARGD) module to estimate the residual of the sensing matrix and degradation matrix . The iterative process is divided into shallow spatial–spectral feature extraction and deep texture refinement, balancing reconstruction quality and computational efficiency. Experimental results demonstrate that RGB-PAHP outperforms existing methods in terms of PSNR, SSIM, and SAM, thereby validating its superiority in NIR-HSI reconstruction.
{"title":"RGB-guided phase-aware hybrid prior network for snapshot near-infrared hyperspectral imaging","authors":"Ajun Shao , Shuting Ma , Xingyu Zhang , Zhuang Zhao , Baohui Guo , Mingze Ma , Jing Han , Yong Peng , Yi Zhang , Lianfa Bai , Guohua Gu , Xin Liu","doi":"10.1016/j.optcom.2026.132922","DOIUrl":"10.1016/j.optcom.2026.132922","url":null,"abstract":"<div><div>Near-infrared hyperspectral images (NIR-HSIs, 900–1700 nm) offer rich spectral information and strong haze-penetrating capability, but their performance is often constrained by sensor noise, leading to low signal-to-noise ratio (SNR), diminished contrast, and texture degradation. In contrast, RGB cameras offer higher SNR and richer texture details while being low-cost and widely accessible, thus serving as effective priors to enhance reconstruction of NIR-HSI. This paper propose an RGB-Guided Phase-Aware Hybrid Prior (RGB-PAHP) method within a dual-camera system, where an RGB camera is integrated into a coded aperture snapshot spectral imaging (CASSI) architecture. A multi-scale RGB feature extraction module (RGB-FE) is designed to fully exploit spatial details from RGB images, effectively guiding the reconstruction of NIR-HSI with high SNR. Furthermore, the method employs a deep unfolding network entirely based on multilayer perceptron (MLP), and introduces a Degradation-Aware Residual Gradient Descent (DARGD) module to estimate the residual of the sensing matrix <span><math><mrow><mi>Φ</mi></mrow></math></span> and degradation matrix <span><math><mrow><mover><mi>Φ</mi><mo>ˆ</mo></mover></mrow></math></span>. The iterative process is divided into shallow spatial–spectral feature extraction and deep texture refinement, balancing reconstruction quality and computational efficiency. Experimental results demonstrate that RGB-PAHP outperforms existing methods in terms of PSNR, SSIM, and SAM, thereby validating its superiority in NIR-HSI reconstruction.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132922"},"PeriodicalIF":2.5,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080128","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}
Mode division multiplexing (MDM) technology has been regarded as one of the most effective methods capable of improving fiber transmission capacity. In the case, modal crosstalk in few-mode fibers and nodes would become the potential limiting factor of long-haul fiber transmission and large network coverage. We propose an all-optical crosstalk suppression scheme based on a single semiconductor optical amplifier (SOA), with application to the optical MDM switching nodes. The feasibility of this scheme is experimentally demonstrated by optimizing the injection current, pump-to-signal power ratio (PSPR) and input signal-to-crosstalk ratio (SXR). The suppression performance for identical-frequency crosstalk is evaluated by inserting the single-SOA regenerator into a two-mode switching node and the error vector magnitude (EVM) for 10 Gb/s QPSK signals can be reduced by 13 % relative to the case without regeneration when the input SXR is 6 dB. On the basis of the single-SOA regenerator, the cascading performance of switching nodes and a double-stage SOA scheme for wavelength preserving are also discussed by simulation. It is shown that the SOA-based crosstalk suppression scheme is applied to the future multi-dimensional switching nodes and networks.
{"title":"Crosstalk suppression in mode-division-multiplexing optical switching nodes using a single SOA-based regenerator","authors":"Xinyu Ma, Baojian Wu, Xintong Lu, Yanjun Chen, Yihan Wang, Feng Wen, Kun Qiu","doi":"10.1016/j.optcom.2026.132945","DOIUrl":"10.1016/j.optcom.2026.132945","url":null,"abstract":"<div><div>Mode division multiplexing (MDM) technology has been regarded as one of the most effective methods capable of improving fiber transmission capacity. In the case, modal crosstalk in few-mode fibers and nodes would become the potential limiting factor of long-haul fiber transmission and large network coverage. We propose an all-optical crosstalk suppression scheme based on a single semiconductor optical amplifier (SOA), with application to the optical MDM switching nodes. The feasibility of this scheme is experimentally demonstrated by optimizing the injection current, pump-to-signal power ratio (PSPR) and input signal-to-crosstalk ratio (SXR). The suppression performance for identical-frequency crosstalk is evaluated by inserting the single-SOA regenerator into a two-mode switching node and the error vector magnitude (EVM) for 10 Gb/s QPSK signals can be reduced by 13 % relative to the case without regeneration when the input SXR is 6 dB. On the basis of the single-SOA regenerator, the cascading performance of switching nodes and a double-stage SOA scheme for wavelength preserving are also discussed by simulation. It is shown that the SOA-based crosstalk suppression scheme is applied to the future multi-dimensional switching nodes and networks.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132945"},"PeriodicalIF":2.5,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080068","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 : 2026-01-22DOI: 10.1016/j.optcom.2026.132944
Xingyu Feng, Xinyan Wang, Yaowei Dai, Peng Gao, Cong Chen, Ying Zhang, Junfeng Fang, Hongfei Ma, Qiyao Wang, Hai Liu
The absorption or resonance wavelengths of certain gas molecules and biological macromolecules lie within the mid-infrared band, leading many researchers to focus on sensor design for this spectral region. However, current mid-infrared metasurface sensors typically possess only a single refractive index (RI) sensing parameter, with limited research dedicated to dual-parameter sensing of both RI and temperature. Furthermore, Quasi-Bound States in the Continuum (Q-BIC) can enhance light-matter interactions, thereby improving metasurface sensing performance. Therefore, this study proposes a high-performance, all-dielectric metasurface-based dual-parameter sensor operating in the mid-infrared band, leveraging Q-BIC. A simple perforation design breaks the structural symmetry, forming a magnetic dipole-dominated Q-BIC, which correlates the environmental RI with the material intrinsic RI, enabling exceptional dual-parameter sensing in the mid-infrared. For RI sensing, the maximum sensitivity achieved is 510.12 nm/RIU, the highest Figure of Merit (FoM) reaches 739.37 RIU−1, and the maximum Quality factor (Q-factor) is 11189.17. For temperature sensing, the maximum sensitivity is 0.30376 nm/°C, the highest FoM reaches 0.2217 °C-1, and the maximum Q-factor is 2496.54, both demonstrating excellent linear responses. Additionally, this structure can function as a polarization-dependent optical switch, with a transmission difference reaching 0.99448. This metasurface sensor holds significant application potential in fields such as security monitoring and biomedical detection.
{"title":"Realizing mid-infrared refractive index and temperature sensing of an all-dielectric metasurface based on Q-BIC","authors":"Xingyu Feng, Xinyan Wang, Yaowei Dai, Peng Gao, Cong Chen, Ying Zhang, Junfeng Fang, Hongfei Ma, Qiyao Wang, Hai Liu","doi":"10.1016/j.optcom.2026.132944","DOIUrl":"10.1016/j.optcom.2026.132944","url":null,"abstract":"<div><div>The absorption or resonance wavelengths of certain gas molecules and biological macromolecules lie within the mid-infrared band, leading many researchers to focus on sensor design for this spectral region. However, current mid-infrared metasurface sensors typically possess only a single refractive index (RI) sensing parameter, with limited research dedicated to dual-parameter sensing of both RI and temperature. Furthermore, Quasi-Bound States in the Continuum (Q-BIC) can enhance light-matter interactions, thereby improving metasurface sensing performance. Therefore, this study proposes a high-performance, all-dielectric metasurface-based dual-parameter sensor operating in the mid-infrared band, leveraging Q-BIC. A simple perforation design breaks the structural symmetry, forming a magnetic dipole-dominated Q-BIC, which correlates the environmental RI with the material intrinsic RI, enabling exceptional dual-parameter sensing in the mid-infrared. For RI sensing, the maximum sensitivity achieved is 510.12 nm/RIU, the highest Figure of Merit (FoM) reaches 739.37 RIU<sup>−1</sup>, and the maximum Quality factor (Q-factor) is 11189.17. For temperature sensing, the maximum sensitivity is 0.30376 nm/°C, the highest FoM reaches 0.2217 °C<sup>-1</sup>, and the maximum Q-factor is 2496.54, both demonstrating excellent linear responses. Additionally, this structure can function as a polarization-dependent optical switch, with a transmission difference reaching 0.99448. This metasurface sensor holds significant application potential in fields such as security monitoring and biomedical detection.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132944"},"PeriodicalIF":2.5,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080071","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 : 2026-01-22DOI: 10.1016/j.optcom.2026.132951
Jingjing Wu , Xueyao Song
In the single-pixel imaging (SPI) process, the illumination patterns need to be projected onto the object surface to modulate and sample the object information. If the illumination pattern is defocused, it will cause blurring in the SPI results. This paper proposes a method using spatially multiplexed phase modulation to generate pseudo non-diffracting structured light pattern, such as random binary patterns, and applies it to SPI, thereby extending the axial imaging range of SPI. Experimental results show that the generated non-diffracting structured light can maintain its pattern stable and unchanged within the designed nondiffracting distance, achieving high-quality SPI imaging even at low sampling rates. This method can obtain clear images without requiring precise focusing, enable SPI for multiple objects along the axial direction simultaneously, and can also be applied to SPI for axially moving objects.
{"title":"Single-pixel imaging based on pseudo non-diffracting structured light modulation","authors":"Jingjing Wu , Xueyao Song","doi":"10.1016/j.optcom.2026.132951","DOIUrl":"10.1016/j.optcom.2026.132951","url":null,"abstract":"<div><div>In the single-pixel imaging (SPI) process, the illumination patterns need to be projected onto the object surface to modulate and sample the object information. If the illumination pattern is defocused, it will cause blurring in the SPI results. This paper proposes a method using spatially multiplexed phase modulation to generate pseudo non-diffracting structured light pattern, such as random binary patterns, and applies it to SPI, thereby extending the axial imaging range of SPI. Experimental results show that the generated non-diffracting structured light can maintain its pattern stable and unchanged within the designed nondiffracting distance, achieving high-quality SPI imaging even at low sampling rates. This method can obtain clear images without requiring precise focusing, enable SPI for multiple objects along the axial direction simultaneously, and can also be applied to SPI for axially moving objects.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132951"},"PeriodicalIF":2.5,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026028","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 : 2026-01-22DOI: 10.1016/j.optcom.2026.132947
Silun Du , Tianshu Wang , Gang Deng , Baoqun Li , Yunhan Deng , Yibing Chen , Yuxia Song
Research on micro-nano optical materials and device technologies has received significant attention in recent years, as the integration of micro-nano fabrication with optical device engineering has dramatically accelerated the advancement of optoelectronic systems. Among various micro-nano structures, micro-nano fibers (MNFs) have emerged as highly versatile platforms for ultrafast fiber laser development due to their unique optical properties. In this work, we demonstrate an all-fiber "Figure 9" thulium-doped fiber laser incorporating a tapered MNF structure. By introducing a polarization controller (PC) and a 12 cm, highly doped, polarization-maintaining gain fiber into an otherwise non-PM cavity, a Lyot-filter-like effect is produced, enabling flexible tuning of both the output wavelength and the number of pulses. The laser generates ultrafast pulses with a fundamental repetition rate exceeding 120 MHz which significantly exceeding the typical sub-50 MHz rates of most all-fiber "Figure 9" thulium systems, a pulse duration of 376 fs, an average output power of 56.37 mW, a wavelength-tuning range greater than 35 nm, and a signal-to-noise ratio (SNR) above 55 dB. Furthermore, the impacts of the ultrashort resonator configuration and the optical characteristics of the tapered MNF on the spectral and temporal properties were systematically analyzed. The demonstrated high-repetition-rate all-fiber laser shows strong potential for applications in precision micromachining, biomedical imaging, ultrafast spectroscopy, and nonlinear optics.
{"title":"All-fiber thulium-doped 120 MHz fundamental frequency mode-locked laser via a high-nonlinearity MNF","authors":"Silun Du , Tianshu Wang , Gang Deng , Baoqun Li , Yunhan Deng , Yibing Chen , Yuxia Song","doi":"10.1016/j.optcom.2026.132947","DOIUrl":"10.1016/j.optcom.2026.132947","url":null,"abstract":"<div><div>Research on micro-nano optical materials and device technologies has received significant attention in recent years, as the integration of micro-nano fabrication with optical device engineering has dramatically accelerated the advancement of optoelectronic systems. Among various micro-nano structures, micro-nano fibers (MNFs) have emerged as highly versatile platforms for ultrafast fiber laser development due to their unique optical properties. In this work, we demonstrate an all-fiber \"Figure 9\" thulium-doped fiber laser incorporating a tapered MNF structure. By introducing a polarization controller (PC) and a 12 cm, highly doped, polarization-maintaining gain fiber into an otherwise non-PM cavity, a Lyot-filter-like effect is produced, enabling flexible tuning of both the output wavelength and the number of pulses. The laser generates ultrafast pulses with a fundamental repetition rate exceeding 120 MHz which significantly exceeding the typical sub-50 MHz rates of most all-fiber \"Figure 9\" thulium systems, a pulse duration of 376 fs, an average output power of 56.37 mW, a wavelength-tuning range greater than 35 nm, and a signal-to-noise ratio (SNR) above 55 dB. Furthermore, the impacts of the ultrashort resonator configuration and the optical characteristics of the tapered MNF on the spectral and temporal properties were systematically analyzed. The demonstrated high-repetition-rate all-fiber laser shows strong potential for applications in precision micromachining, biomedical imaging, ultrafast spectroscopy, and nonlinear optics.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132947"},"PeriodicalIF":2.5,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080156","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}
Currently, the average output power of single-beam optical parametric amplification (OPA) is limited to the 100-W level due to the constraints of the average power of the pump laser. OPA pumped by multiple laser beams can transfer the energy from multiple pump lasers to the same signal laser through nonlinear amplification, and it has great potential for increasing the average power of the OPA system. In this paper, a four-beam 1030-nm ∼1-ps laser-pumped OPA system using a KTA crystal is established to investigate the high-power and high-efficiency amplification operation. Signal laser output at 1.62 μm with an average power greater than 6.5 W and efficiency larger than 15% has been achieved, thereby verifying the feasibility of achieving high average power through multi-beam pumped OPA. By adjusting the non-collinear angles of each pump beam, amplification bandwidth of the signal beam can be expanded from 14.8 nm to 33.1 nm. This provides a viable solution for spectral synthesis and laser pulse compression with multi-beam pumped OPA. Additionally, two-dimension array of frequency-doubling and sum-frequency generation in the multi-beam pumped OPA system is analyzed, offering new insights into exploring complex spatiotemporal nonlinear processes.
{"title":"High-average-power 1.62-μm optical parametric amplification using four-beam pumping","authors":"Mingwei Mao, Ruiming Wang, Zhihui Yang, Yuan Tang, Yulong Tang","doi":"10.1016/j.optcom.2026.132950","DOIUrl":"10.1016/j.optcom.2026.132950","url":null,"abstract":"<div><div>Currently, the average output power of single-beam optical parametric amplification (OPA) is limited to the 100-W level due to the constraints of the average power of the pump laser. OPA pumped by multiple laser beams can transfer the energy from multiple pump lasers to the same signal laser through nonlinear amplification, and it has great potential for increasing the average power of the OPA system. In this paper, a four-beam 1030-nm ∼1-ps laser-pumped OPA system using a KTA crystal is established to investigate the high-power and high-efficiency amplification operation. Signal laser output at 1.62 μm with an average power greater than 6.5 W and efficiency larger than 15% has been achieved, thereby verifying the feasibility of achieving high average power through multi-beam pumped OPA. By adjusting the non-collinear angles of each pump beam, amplification bandwidth of the signal beam can be expanded from 14.8 nm to 33.1 nm. This provides a viable solution for spectral synthesis and laser pulse compression with multi-beam pumped OPA. Additionally, two-dimension array of frequency-doubling and sum-frequency generation in the multi-beam pumped OPA system is analyzed, offering new insights into exploring complex spatiotemporal nonlinear processes.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132950"},"PeriodicalIF":2.5,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080064","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 : 2026-01-21DOI: 10.1016/j.optcom.2026.132942
Xiaohui Wang , Zhiang Gao , Chenglong Jiang , Yan Hong , Shanman Cheng , Zewen Jing , Wentao Cao , Liang Xu , Xinchen Ji , Hui Zhang , Jiawei Rui , Yingxiong Song , Fufei Pang , Liyun Zhuang , Song Yang , Xiaofeng He , Yongfeng Ju , Yinshan Yu
An orbital angular momentum (OAM) has been promisingly adopted and propagated over an optical fiber by a space-division multiplexing (SDM) for enhancing the channel capacity and propagation distance, where the system performances are inevitably disturbed by various factors. Plenty of methods have been investigated for mitigating signal interruption in the OAM-based mode group (OMG) multiplexing system, which inevitably increases the cost of device, complexities and times. For mitigating the aforementioned issues, a multiple-path receiving (MPR) method is proposed by receiving two conjugated OAM modes within an OMG for demodulating the received the multiplexed OMGs. For supporting the OAM mode propagations, a weakly-coupled OAM fiber (WCOF) is fabricated, where a lower refraction index contrast (less than 1 %) between ring-core layer and cladding is achieved for reducing the propagation loss (PL) of the supported modes. A maximal PL of 0.289 dB/km in the supported four OMGs is measured by an optical time domain reflectometry, which depicts that the proposed WOCF with a low propagation loss can be potentially used for OAG-based multiplexing through a longer propagation distance. Besides, an experiment platform is also built for showing the feasibility of the proposed method. The detected intensity and interference images depict that the transmitted three OAM modes are successfully received, respectively. Moreover, a bit error rate (BER) is also adopted to evaluate the system performances with/without MPR. The measured BER results show that an improvement of 2.30/2.39/2.98 dBm for OMG1/2/3 can be achieved when the proposed MPR is employed. Moreover, the measured BERs also demonstrate that the BERs degrade as the WCOF length/data rate increases, respectively. Besides, all measured BERs are below the threshold of hard forward error correction (HFEC) at −21 dBm from 1530 nm to 1625 nm, which implies that the proposed method can be utilized in the “C + L” waveband.
{"title":"Mitigating signal interruption of OAM- and fiber-based mode group multiplexing by receiving two conjugated OAM beams within an OAM mode group","authors":"Xiaohui Wang , Zhiang Gao , Chenglong Jiang , Yan Hong , Shanman Cheng , Zewen Jing , Wentao Cao , Liang Xu , Xinchen Ji , Hui Zhang , Jiawei Rui , Yingxiong Song , Fufei Pang , Liyun Zhuang , Song Yang , Xiaofeng He , Yongfeng Ju , Yinshan Yu","doi":"10.1016/j.optcom.2026.132942","DOIUrl":"10.1016/j.optcom.2026.132942","url":null,"abstract":"<div><div>An orbital angular momentum (OAM) has been promisingly adopted and propagated over an optical fiber by a space-division multiplexing (SDM) for enhancing the channel capacity and propagation distance, where the system performances are inevitably disturbed by various factors. Plenty of methods have been investigated for mitigating signal interruption in the OAM-based mode group (OMG) multiplexing system, which inevitably increases the cost of device, complexities and times. For mitigating the aforementioned issues, a multiple-path receiving (MPR) method is proposed by receiving two conjugated OAM modes within an OMG for demodulating the received the multiplexed OMGs. For supporting the OAM mode propagations, a weakly-coupled OAM fiber (WCOF) is fabricated, where a lower refraction index contrast (less than 1 %) between ring-core layer and cladding is achieved for reducing the propagation loss (PL) of the supported modes. A maximal PL of 0.289 dB/km in the supported four OMGs is measured by an optical time domain reflectometry, which depicts that the proposed WOCF with a low propagation loss can be potentially used for OAG-based multiplexing through a longer propagation distance. Besides, an experiment platform is also built for showing the feasibility of the proposed method. The detected intensity and interference images depict that the transmitted three OAM modes are successfully received, respectively. Moreover, a bit error rate (BER) is also adopted to evaluate the system performances with/without MPR. The measured BER results show that an improvement of 2.30/2.39/2.98 dBm for OMG1/2/3 can be achieved when the proposed MPR is employed. Moreover, the measured BERs also demonstrate that the BERs degrade as the WCOF length/data rate increases, respectively. Besides, all measured BERs are below the threshold of hard forward error correction (HFEC) at −21 dBm from 1530 nm to 1625 nm, which implies that the proposed method can be utilized in the “C + L” waveband.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132942"},"PeriodicalIF":2.5,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026027","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 : 2026-01-21DOI: 10.1016/j.optcom.2026.132943
Xuan Cao , Fuxiao Xu , Zhenjia Li , Jiacheng He , Guoshuai Zhao , Guojie Tu
The demand for three-dimensional (3D) surface topography measurement of objects in modern precision manufacturing has significantly increased. Among non-contact optical measurement methods, the 3D surface topography measurement scheme based on frequency modulated continuous wave (FMCW) ranging technology exhibits notable advantages in measurement accuracy and resistance to ambient light interference. However, similar to other ranging-based schemes, this approach mostly relies on mechanical scanning, leading to a complex system structure and high manufacturing costs. To address this challenge, this study proposes a 3D surface topography measurement scheme based on a Mach-Zehnder interferometer (MZI) and array-detection FMCW, utilizing a low-cost vertical cavity surface emitting laser (VCSEL). The main practical advantage of this scheme lies in replacing mechanical scanning with array detection, which significantly simplifies the system structure and reduces manufacturing costs while maintaining high measurement performance over long distances. Experimental results demonstrate that the proposed scheme achieves a ranging accuracy of 0.0148 mm at a distance of 5 m, with a measurement range of up to 33 mm.
{"title":"Topography measurement system based on array-detection FMCW","authors":"Xuan Cao , Fuxiao Xu , Zhenjia Li , Jiacheng He , Guoshuai Zhao , Guojie Tu","doi":"10.1016/j.optcom.2026.132943","DOIUrl":"10.1016/j.optcom.2026.132943","url":null,"abstract":"<div><div>The demand for three-dimensional (3D) surface topography measurement of objects in modern precision manufacturing has significantly increased. Among non-contact optical measurement methods, the 3D surface topography measurement scheme based on frequency modulated continuous wave (FMCW) ranging technology exhibits notable advantages in measurement accuracy and resistance to ambient light interference. However, similar to other ranging-based schemes, this approach mostly relies on mechanical scanning, leading to a complex system structure and high manufacturing costs. To address this challenge, this study proposes a 3D surface topography measurement scheme based on a Mach-Zehnder interferometer (MZI) and array-detection FMCW, utilizing a low-cost vertical cavity surface emitting laser (VCSEL). The main practical advantage of this scheme lies in replacing mechanical scanning with array detection, which significantly simplifies the system structure and reduces manufacturing costs while maintaining high measurement performance over long distances. Experimental results demonstrate that the proposed scheme achieves a ranging accuracy of 0.0148 mm at a distance of 5 m, with a measurement range of up to 33 mm.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132943"},"PeriodicalIF":2.5,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080130","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 : 2026-01-21DOI: 10.1016/j.optcom.2026.132941
Jiamin Fan , Yu Qin , Tingyu Fu , Jie Zhu , Yichun Shen , Limin Xiao , Mingyi Gao
In this work, we propose a hierarchical multiplexed multiple-input multiple-output (MIMO) equalizer with adaptive compensation capabilities, synergistically integrated into a polarization-division multiplexed and probabilistically shaped 1024-QAM coherent optical transmission system. Through hierarchical progressive compensation, the architecture achieves deep synergistic compensation for polarization crosstalk, IQ gain and phase imbalance, timing skew, and residual inter-symbol interference. This architecture is experimentally validated over a 5-km double nested anti-resonant nodeless fiber link operating at 20 GBaud. The proposed equalizer effectively mitigates signal impairments and inter-channel crosstalk inherent to high-order modulation formats, while maintaining spectral efficiency. Finally, the three-stage MIMO equalizer achieves an approximately 1.2-dB improvement in optical signal-to-noise ratio sensitivity over the two-stage counterpart at the soft-decision forward error correction threshold, alongside a spectral efficiency of 16.19 bits/s/Hz.
{"title":"Hierarchical MIMO equalizer for PDM PS-1024-QAM coherent optical transmission over DNANF","authors":"Jiamin Fan , Yu Qin , Tingyu Fu , Jie Zhu , Yichun Shen , Limin Xiao , Mingyi Gao","doi":"10.1016/j.optcom.2026.132941","DOIUrl":"10.1016/j.optcom.2026.132941","url":null,"abstract":"<div><div>In this work, we propose a hierarchical multiplexed multiple-input multiple-output (MIMO) equalizer with adaptive compensation capabilities, synergistically integrated into a polarization-division multiplexed and probabilistically shaped 1024-QAM coherent optical transmission system. Through hierarchical progressive compensation, the architecture achieves deep synergistic compensation for polarization crosstalk, IQ gain and phase imbalance, timing skew, and residual inter-symbol interference. This architecture is experimentally validated over a 5-km double nested anti-resonant nodeless fiber link operating at 20 GBaud. The proposed equalizer effectively mitigates signal impairments and inter-channel crosstalk inherent to high-order modulation formats, while maintaining spectral efficiency. Finally, the three-stage MIMO equalizer achieves an approximately 1.2-dB improvement in optical signal-to-noise ratio sensitivity over the two-stage counterpart at the soft-decision forward error correction threshold, alongside a spectral efficiency of 16.19 bits/s/Hz.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132941"},"PeriodicalIF":2.5,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080131","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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