Pub Date : 2024-10-10DOI: 10.1016/j.yofte.2024.103990
Hui Yang, Shuteng Cui, Anlin Yi
We introduce an optical signal-to-noise ratio (OSNR) monitoring method tailored for elastic optical networks employing probabilistic shaping (PS). The OSNR characteristics of PS signals are represented by three-dimensional density histogram matrices with dynamic power function factors and are identified through a lightweight convolutional neural network (CNN). The results show that the mean absolute error of OSNR monitoring can be reduced to less than 0.12-dB and 0.34-dB in back-to-back and optical fiber transmission settings for the four M-QAM modulation formats correspondingly. Additionally, we leverage transfer learning in conjunction with the CNN to facilitate OSNR monitoring in extended-distance scenarios. The results highlight the efficacy of transfer learning in rapidly adapting CNN architectures to varying transmission distances. It is anticipated that the proposed OSNR monitoring scheme shows potential for integration into future elastic optical networks.
{"title":"An OSNR monitoring scheme for elastic optical networks with probabilistic shaping","authors":"Hui Yang, Shuteng Cui, Anlin Yi","doi":"10.1016/j.yofte.2024.103990","DOIUrl":"10.1016/j.yofte.2024.103990","url":null,"abstract":"<div><div>We introduce an optical signal-to-noise ratio (OSNR) monitoring method tailored for elastic optical networks employing probabilistic shaping (PS). The OSNR characteristics of PS signals are represented by three-dimensional density histogram matrices with dynamic power function factors and are identified through a lightweight convolutional neural network (CNN). The results show that the mean absolute error of OSNR monitoring can be reduced to less than 0.12-dB and 0.34-dB in back-to-back and optical fiber transmission settings for the four M-QAM modulation formats correspondingly. Additionally, we leverage transfer learning in conjunction with the CNN to facilitate OSNR monitoring in extended-distance scenarios. The results highlight the efficacy of transfer learning in rapidly adapting CNN architectures to varying transmission distances. It is anticipated that the proposed OSNR monitoring scheme shows potential for integration into future elastic optical networks.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"88 ","pages":"Article 103990"},"PeriodicalIF":2.6,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1016/j.yofte.2024.103999
Kaixin Li , Xiaoyu Zhao , Yu Wei , Shuaimeng Li , Weiyu Fan , Guomei Wang , Wenfei Zhang , Caixun Bai , Cheng Lu , Yangyang Wang , Huanian Zhang
This paper reports on the generation of third-order harmonic mode-locking, double-pulse phenomena, and conventional solitons in an erbium-doped fiber laser using Cr2Si2Te6 as a saturable absorber (SA). The double-balance probing method was employed to examine the nonlinear characteristics of Cr2Si2Te6-SA. Its modulation depth is 2.35 %, and its saturation intensity is 29.74 MW/cm2. We discovered conventional soliton functioning with a center wavelength of 1561.8 nm at a pump power of 34.76 mW. It has a repetition frequency of 6.76 MHz and a signal-to-noise ratio of 45 dB. As the pump power increased, the traditional soliton was able to maintain its existence in the range of 34.76 mW to 80.96 mW. The maximum output power reaches 1.1 mW when the pump power is 80.96 mW, and the maximum single-pulse energy of the conventional soliton is 0.16 nJ. Furthermore, we observed third-order harmonic mode-locking and double-pulse phenomena at pump outputs of 53.65 mW and 71.16 mW. The experimental findings demonstrate the excellent nonlinear effect of the SA based on Cr2Si2Te6. In ultrashort-pulse fiber lasers, Cr2Si2Te6 nanosheets can be employed as an efficient saturable absorption material.
{"title":"Passively mode-locking fiber laser based on Cr2Si2Te6 saturable absorber","authors":"Kaixin Li , Xiaoyu Zhao , Yu Wei , Shuaimeng Li , Weiyu Fan , Guomei Wang , Wenfei Zhang , Caixun Bai , Cheng Lu , Yangyang Wang , Huanian Zhang","doi":"10.1016/j.yofte.2024.103999","DOIUrl":"10.1016/j.yofte.2024.103999","url":null,"abstract":"<div><div>This paper reports on the generation of third-order harmonic mode-locking, double-pulse phenomena, and conventional solitons in an erbium-doped fiber laser using Cr<sub>2</sub>Si<sub>2</sub>Te<sub>6</sub> as a saturable absorber (SA). The double-balance probing method was employed to examine the nonlinear characteristics of Cr<sub>2</sub>Si<sub>2</sub>Te<sub>6</sub>-SA. Its modulation depth is 2.35 %, and its saturation intensity is 29.74 MW/cm<sup>2</sup>. We discovered conventional soliton functioning with a center wavelength of 1561.8 nm at a pump power of 34.76 mW. It has a repetition frequency of 6.76 MHz and a signal-to-noise ratio of 45 dB. As the pump power increased, the traditional soliton was able to maintain its existence in the range of 34.76 mW to 80.96 mW. The maximum output power reaches 1.1 mW when the pump power is 80.96 mW, and the maximum single-pulse energy of the conventional soliton is 0.16 nJ. Furthermore, we observed third-order harmonic mode-locking and double-pulse phenomena at pump outputs of 53.65 mW and 71.16 mW. The experimental findings demonstrate the excellent nonlinear effect of the SA based on Cr<sub>2</sub>Si<sub>2</sub>Te<sub>6</sub>. In ultrashort-pulse fiber lasers, Cr<sub>2</sub>Si<sub>2</sub>Te<sub>6</sub> nanosheets can be employed as an efficient saturable absorption material.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"88 ","pages":"Article 103999"},"PeriodicalIF":2.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-08DOI: 10.1016/j.yofte.2024.103989
Bo He , Jingjing Wang , Ziyin Chen , Haojie Yang , Yong Feng , Bin Yang , Qieming Shi , Jinqian Qian , Elfed Lewis , Tao Geng , Weimin Sun
In this paper, two approaches have been adopted to optimize the design of optical fiber X-ray sensors (OFXS). One approach involves using the hemisphere tip structure OFXS, while the other considers increasing the embedding depth of the scintillator in the embedded structure OFXS. The four OFXS designs considered include a 1 mm diameter hemispherical tip structure as well as embedded structure OFXSs with embedding depths of 1 mm, 3 mm, and 5 mm. Experimental results indicate that all four OFXSs exhibit a dose linearity above 0.999938 and dose rate linearity above 0.99991. The optical signal generated by hemisphere tip structure OFXS is 2–3 times higher compared to the embedded structure OFXSs. In the case of the embedded OFXS, increasing the embedding depth cannot effectively improve its sensitivity. And when measuring percentage depth dose (PDD) characteristics, no significant difference was observed for the four OFXSs. In addition, compared to the PDD curve measured using ionization chamber (IC), all OFXS exhibit an over-response phenomenon. These results show that the over-response phenomenon is not related to the structure of OFXS or the volume of scintillator, but only to the scintillator material. Therefore, subsequent calibration of OFXS needs to focus on studying the luminescence characteristics of the scintillator.
{"title":"Optimizing design of inorganic scintillator optical fiber X-ray sensors","authors":"Bo He , Jingjing Wang , Ziyin Chen , Haojie Yang , Yong Feng , Bin Yang , Qieming Shi , Jinqian Qian , Elfed Lewis , Tao Geng , Weimin Sun","doi":"10.1016/j.yofte.2024.103989","DOIUrl":"10.1016/j.yofte.2024.103989","url":null,"abstract":"<div><div>In this paper, two approaches have been adopted to optimize the design of optical fiber X-ray sensors (OFXS). One approach involves using the hemisphere tip structure OFXS, while the other considers increasing the embedding depth of the scintillator in the embedded structure OFXS. The four OFXS designs considered include a 1 mm diameter hemispherical tip structure as well as embedded structure OFXSs with embedding depths of 1 mm, 3 mm, and 5 mm. Experimental results indicate that all four OFXSs exhibit a dose linearity above 0.999938 and dose rate linearity above 0.99991. The optical signal generated by hemisphere tip structure OFXS is 2–3 times higher compared to the embedded structure OFXSs. In the case of the embedded OFXS, increasing the embedding depth cannot effectively improve its sensitivity. And when measuring percentage depth dose (PDD) characteristics, no significant difference was observed for the four OFXSs. In addition, compared to the PDD curve measured using ionization chamber (IC), all OFXS exhibit an over-response phenomenon. These results show that the over-response phenomenon is not related to the structure of OFXS or the volume of scintillator, but only to the scintillator material. Therefore, subsequent calibration of OFXS needs to focus on studying the luminescence characteristics of the scintillator.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"88 ","pages":"Article 103989"},"PeriodicalIF":2.6,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-05DOI: 10.1016/j.yofte.2024.103997
Jindong Ma , Menglong Ma , Nan Zhang , Jiangjie Zhu , Ming Liu , Xiaoying Tang , Huanhuan Liu , Perry Ping Shum
We have proposed and demonstrated a high-repetition-rate ultrashort pulse fiber amplification system based on a wavelength-tunable oscillator. This fiber amplification system produces an average power exceeding 20 W in bursts of 200 pulses with a 578 MHz intra-burst pulse repetition rate and a 1 MHz burst repetition rate. The center wavelength of the amplified pulses can be tuned from 1030 to 1080 nm. By utilizing pre-chirp management nonlinear amplification technique, the achieved shortest pulse duration is 27 fs with an average power of 25 W at 1032 nm. For all the amplified pulses with different wavelengths, the pulse duration after optimal compression is below 60 fs. To the best of our knowledge, this is the first time that a widely wavelength-tunable high-power laser with a repetition rate exceeding 100 MHz and a pulse duration of several tens of femtoseconds has been realized. Additionally, using only common double-cladding Yb-doped fiber as the gain fiber, without any large-mode-area Yb-doped photonic crystal fiber or rod-type Yb-doped fiber, makes the system compact and reliable due to the simple fusion operation.
{"title":"Widely wavelength-tunable high-repetition-rate femtosecond pulse source with highest average power up to 28 W","authors":"Jindong Ma , Menglong Ma , Nan Zhang , Jiangjie Zhu , Ming Liu , Xiaoying Tang , Huanhuan Liu , Perry Ping Shum","doi":"10.1016/j.yofte.2024.103997","DOIUrl":"10.1016/j.yofte.2024.103997","url":null,"abstract":"<div><div>We have proposed and demonstrated a high-repetition-rate ultrashort pulse fiber amplification system based on a wavelength-tunable oscillator. This fiber amplification system produces an average power exceeding 20 W in bursts of 200 pulses with a 578 MHz intra-burst pulse repetition rate and a 1 MHz burst repetition rate. The center wavelength of the amplified pulses can be tuned from 1030 to 1080 nm. By utilizing pre-chirp management nonlinear amplification technique, the achieved shortest pulse duration is 27 fs with an average power of 25 W at 1032 nm. For all the amplified pulses with different wavelengths, the pulse duration after optimal compression is below 60 fs. To the best of our knowledge, this is the first time that a widely wavelength-tunable high-power laser with a repetition rate exceeding 100 MHz and a pulse duration of several tens of femtoseconds has been realized. Additionally, using only common double-cladding Yb-doped fiber as the gain fiber, without any large-mode-area Yb-doped photonic crystal fiber or rod-type Yb-doped fiber, makes the system compact and reliable due to the simple fusion operation.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"88 ","pages":"Article 103997"},"PeriodicalIF":2.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-05DOI: 10.1016/j.yofte.2024.103994
Linzhi Yao , Tao Wang , Chunlei Jiang , Qian Zhao , Yuan Sui , Yan Lu , Yunkai Wang , Yu Sun , Zhicheng Cong , Taiji Dong
We propose a multi-particle sorting method based on single optical fiber tweezer particle-trapped signals. When particles are trapped to the optical axis, the instantaneous trapped signal is collected by the photodetector. There are significant differences in the instantaneous trapped signal intensity for particles with different refractive indices. Specifically, the variation in instantaneous trapped signal intensity correlates well with changes in the refractive index of the particles in a linear relationship. We conducted 60 sets of experiments, which showed that the method accurately sorts yeast cells, silica (SiO2) microspheres, and polystyrene (PS) microspheres. Additionally, the method’s simple structure, high accuracy, ability to simultaneously sort multiple particles, and potential to handle large quantities of particles provide a new approach to particle identification and detection. Consequently, this method is widely used in chemistry, microbiology, and medical diagnostics.
{"title":"Multi-Particle sorting using signals from particles trapped by single optical fiber tweezers","authors":"Linzhi Yao , Tao Wang , Chunlei Jiang , Qian Zhao , Yuan Sui , Yan Lu , Yunkai Wang , Yu Sun , Zhicheng Cong , Taiji Dong","doi":"10.1016/j.yofte.2024.103994","DOIUrl":"10.1016/j.yofte.2024.103994","url":null,"abstract":"<div><div>We propose a multi-particle sorting method based on single optical fiber tweezer particle-trapped signals. When particles are trapped to the optical axis, the instantaneous trapped signal is collected by the photodetector. There are significant differences in the instantaneous trapped signal intensity for particles with different refractive indices. Specifically, the variation in instantaneous trapped signal intensity correlates well with changes in the refractive index of the particles in a linear relationship. We conducted 60 sets of experiments, which showed that the method accurately sorts yeast cells, silica (SiO<sub>2</sub>) microspheres, and polystyrene (PS) microspheres. Additionally, the method’s simple structure, high accuracy, ability to simultaneously sort multiple particles, and potential to handle large quantities of particles provide a new approach to particle identification and detection. Consequently, this method is widely used in chemistry, microbiology, and medical diagnostics.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"88 ","pages":"Article 103994"},"PeriodicalIF":2.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-05DOI: 10.1016/j.yofte.2024.103998
Bibhatsu Kuiri , Aloke Kumar Pathak , Nilanjana Sarkar , Amlan Das , Manish Dev Sharma , Ardhendu Sekhar Patra
Multimode capability in photonic crystal fiber (PCF) is an important feature in fiber development. This study presents an innovative Dual Ring Hollow core PCF (DRH-PCF), designed to support a large number of multimode operations with minimal loss and flat dispersion optimized in the wavelength range of 1.26 µm to 1.66 µm. The DRH-PCF structure comprises a high-purity silica matrix, featuring a unique configuration that includes a hollow core and high indexed Lithium niobate (LiNbO3)-Arsenic trisulfide (As2S3) dual rings of thickness 0.6 µm. This arrangement is complemented by a pattern of strategically placed air holes encircling the fiber. Our PCF is engineered to support an impressive 200 and more orbital angular momentum modes, with low confinement loss (∼10−5 dB/m) and near-flat dispersion (∼3 ps/mm/km) and very large power fraction (∼0.99), while maintaining high mode purity of >95 %. Furthermore, the fiber exhibits a near-flat dispersion profile over a wide spectral range, with a measured dispersion of ∼6 ps/(nm·km) around the operational wavelength. Stability due to fiber bend is also investigated for extreme bend tolerance (Bend radii RB=1cm to 80 cm). Deep Learning prediction is used to train and predict the performance of the fiber and obtained remarkably close results (within 5 %). This combination of features makes our PCF an excellent candidate for diverse applications in high-capacity optical communication systems, sensing technologies, and nonlinear optics.
{"title":"Deep learning prediction of novel hollow core photonic crystal fiber with tuned As2S3 − LiNbO3 ring for multimode applications","authors":"Bibhatsu Kuiri , Aloke Kumar Pathak , Nilanjana Sarkar , Amlan Das , Manish Dev Sharma , Ardhendu Sekhar Patra","doi":"10.1016/j.yofte.2024.103998","DOIUrl":"10.1016/j.yofte.2024.103998","url":null,"abstract":"<div><div>Multimode capability in photonic crystal fiber (PCF) is an important feature in fiber development. This study presents an innovative Dual Ring Hollow core PCF (DRH-PCF), designed to support a large number of multimode operations with minimal loss and flat dispersion optimized in the wavelength range of 1.26 µm to 1.66 µm. The DRH-PCF structure comprises a high-purity silica matrix, featuring a unique configuration that includes a hollow core and high indexed Lithium niobate (LiNbO<sub>3</sub>)-Arsenic trisulfide (As<sub>2</sub>S<sub>3</sub>) dual rings of thickness 0.6 µm. This arrangement is complemented by a pattern of strategically placed air holes encircling the fiber. Our PCF is engineered to support an impressive 200 and more orbital angular momentum modes, with low confinement loss (∼10<sup>−5</sup> dB/m) and near-flat dispersion (∼3 ps/mm/km) and very large power fraction (∼0.99), while maintaining high mode purity of >95 %. Furthermore, the fiber exhibits a near-flat dispersion profile over a wide spectral range, with a measured dispersion of ∼6 ps/(nm·km) around the operational wavelength. Stability due to fiber bend is also investigated for extreme bend tolerance (Bend radii R<sub>B</sub>=1cm to 80 cm). Deep Learning prediction is used to train and predict the performance of the fiber and obtained remarkably close results (within 5 %). This combination of features makes our PCF an excellent candidate for diverse applications in high-capacity optical communication systems, sensing technologies, and nonlinear optics.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"88 ","pages":"Article 103998"},"PeriodicalIF":2.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-04DOI: 10.1016/j.yofte.2024.103995
Arnaldo Leal-Junior , Wilfried Blanc
This paper presents the development of a cost-effective distributed optical fiber sensor for temperature-insensitive assessment of mechanical disturbances along an optical fiber cable. The proposed sensor system uses a nanoparticle (NP)-doped optical fiber with enhanced Rayleigh backscattering to provide higher sensitivity and spatial resolution using the transmission and reflection analysis (TRA) approach, where the transmitted and backscattered optical powers are analyzed as a function of the mechanical disturbance. In addition, Fiber Bragg Gratings (FBGs) are used as wavelength filters to provide the wavelength division multiplexing of the proposed device, which enable the use of 3 different NP-doped optical fiber sections for simultaneous detection of multiple curvature conditions in a cost-effective distributed sensing approach. The sensor characterization tests are performed by means of applying curvature angles from 360° to 1080° at different positions along NP-doped fibers (namely 25 mm, 100 mm and 175 mm) at 4 different temperatures of 25 °C, 30 °C, 40 °C and 50 °C. The results indicate the feasibility of the proposed approach, where the temperature variations lead only to a wavelength shift of the Bragg wavelength, whereas the mechanical disturbances (the curvatures) lead only to variations in the transmitted and reflected optical powers. Thus, by analyzing the transmitted and reflected optical powers in conjunction with the Bragg wavelength shift, it is possible to estimate both the mechanical disturbance amplitude (i.e., curvature angle) and the position along each NP-doped optical fiber section. Results indicate a relative error of around 3 % and 4 % for the mechanical disturbance location and absolute value, respectively. Moreover, the temperature cross-sensitivity in this case is below 2 % considering both amplitude and location of the mechanical disturbance. The proposed approach can be applied in structural health monitoring of different types of structures by integrating the fibers in the structures themselves with the possibility of measuring the strain distribution along the fibers (instead of in different points along the fiber) using a lower cost hardware when compared with similar distributed optical fiber sensing approaches.
{"title":"Temperature-insensitive and cost-effective distributed NP-Doped optical fiber sensors","authors":"Arnaldo Leal-Junior , Wilfried Blanc","doi":"10.1016/j.yofte.2024.103995","DOIUrl":"10.1016/j.yofte.2024.103995","url":null,"abstract":"<div><div>This paper presents the development of a cost-effective distributed optical fiber sensor for temperature-insensitive assessment of mechanical disturbances along an optical fiber cable. The proposed sensor system uses a nanoparticle (NP)-doped optical fiber with enhanced Rayleigh backscattering to provide higher sensitivity and spatial resolution using the transmission and reflection analysis (TRA) approach, where the transmitted and backscattered optical powers are analyzed as a function of the mechanical disturbance. In addition, Fiber Bragg Gratings (FBGs) are used as wavelength filters to provide the wavelength division multiplexing of the proposed device, which enable the use of 3 different NP-doped optical fiber sections for simultaneous detection of multiple curvature conditions in a cost-effective distributed sensing approach. The sensor characterization tests are performed by means of applying curvature angles from 360° to 1080° at different positions along NP-doped fibers (namely 25 mm, 100 mm and 175 mm) at 4 different temperatures of 25 °C, 30 °C, 40 °C and 50 °C. The results indicate the feasibility of the proposed approach, where the temperature variations lead only to a wavelength shift of the Bragg wavelength, whereas the mechanical disturbances (the curvatures) lead only to variations in the transmitted and reflected optical powers. Thus, by analyzing the transmitted and reflected optical powers in conjunction with the Bragg wavelength shift, it is possible to estimate both the mechanical disturbance amplitude (i.e., curvature angle) and the position along each NP-doped optical fiber section. Results indicate a relative error of around 3 % and 4 % for the mechanical disturbance location and absolute value, respectively. Moreover, the temperature cross-sensitivity in this case is below 2 % considering both amplitude and location of the mechanical disturbance. The proposed approach can be applied in structural health monitoring of different types of structures by integrating the fibers in the structures themselves with the possibility of measuring the strain distribution along the fibers (instead of in different points along the fiber) using a lower cost hardware when compared with similar distributed optical fiber sensing approaches.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"88 ","pages":"Article 103995"},"PeriodicalIF":2.6,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Design of heterogeneous 4-core fiber housing a low-latency core and conventional cutoff shifted cores in a standard 125-μm cladding diameter is investigated to enable signal processing delay reduction using common mode impairment. For the low-latency core, 1-μs propagation delay reduction and an optical signal-to-noise ratio (OSNR) comparable to or greater than that of cutoff shifted cores are required. In this paper, we consider an F-doped core and depressed cladding structure with a large effective area as the low-latency core. It can be expected to achieve sufficient group delay reduction of the low-latency core, the OSNR unification among heterogeneous cores, and low inter-core crosstalk in a standard 125-μm cladding diameter. Consequently, we revealed the optimized low-latency core achieving the group delay reduction of 1 μs and the OSNR as same level as the cutoff shifted cores as we expected. The designed heterogeneous 4-core fiber with the standard 125-μm cladding diameter suppressed the inter-core crosstalk to be low enough to support a 1,000-km long transmission. We expect the figure-of-merit (FoM) of the 4-core fiber to be as high as previously reported 4-core fibers, and the FoM improvement are found when the low latency core and cutoff shifted core are placed alternately thanks to the core heterogeneity.
{"title":"Multicore fiber design housing a fluorine-doped low-latency core and cutoff shifted cores","authors":"Yuto Sagae, Takashi Matsui, Takayoshi Mori, Kazuhide Nakajima","doi":"10.1016/j.yofte.2024.103993","DOIUrl":"10.1016/j.yofte.2024.103993","url":null,"abstract":"<div><div>Design of heterogeneous 4-core fiber housing a low-latency core and conventional cutoff shifted cores in a standard 125-μm cladding diameter is investigated to enable signal processing delay reduction using common mode impairment. For the low-latency core, 1-μs propagation delay reduction and an optical signal-to-noise ratio (OSNR) comparable to or greater than that of cutoff shifted cores are required. In this paper, we consider an F-doped core and depressed cladding structure with a large effective area as the low-latency core. It can be expected to achieve sufficient group delay reduction of the low-latency core, the OSNR unification among heterogeneous cores, and low inter-core crosstalk in a standard 125-μm cladding diameter. Consequently, we revealed the optimized low-latency core achieving the group delay reduction of 1 μs and the OSNR as same level as the cutoff shifted cores as we expected. The designed heterogeneous 4-core fiber with the standard 125-μm cladding diameter suppressed the inter-core crosstalk to be low enough to support a 1,000-km long transmission. We expect the figure-of-merit (FoM) of the 4-core fiber to be as high as previously reported 4-core fibers, and the FoM improvement are found when the low latency core and cutoff shifted core are placed alternately thanks to the core heterogeneity.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"88 ","pages":"Article 103993"},"PeriodicalIF":2.6,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.yofte.2024.103991
Yingying Li , Bo Gao , Ying Han , Luyao Zhou , Honglin Wen , Qi Li , He Di , Ge Wu , Lie Liu , Jiayu Huo
Thulium-doped fiber (TDF) lasers are considered ideal platforms for studying 2 µm passively mode-locked fiber lasers. However, previous research primarily focused on soliton generation in TDF lasers, overlooking the switching and transformation between solitons in various states. This paper investigates the switching and transformation of multi-state solitons in TDF lasers based on nonlinear polarization rotation. By properly adjusting the pump power and polarization controller, we observe the switching and transformation between conventional soliton and bound state soliton, between soliton clusters and dual-wavelength soliton. The results were achieved using a simple structure (utilizing only one polarization controller) that exhibited superior repeatability and simplicity compared to a complex configuration (two polarization controllers). The experimental observation of the switching and transformation of multi-state solitons not only provides a deeper understanding of the dynamics of solitons in TDF lasers but also contributes to the design of multifunctional fiber lasers. This is significant for promoting the application of 2 µm fiber lasers.
{"title":"Switching and transformation of multi-state solitons in thulium-doped fiber laser based on nonlinear polarization rotation","authors":"Yingying Li , Bo Gao , Ying Han , Luyao Zhou , Honglin Wen , Qi Li , He Di , Ge Wu , Lie Liu , Jiayu Huo","doi":"10.1016/j.yofte.2024.103991","DOIUrl":"10.1016/j.yofte.2024.103991","url":null,"abstract":"<div><div>Thulium-doped fiber (TDF) lasers are considered ideal platforms for studying 2 µm passively mode-locked fiber lasers. However, previous research primarily focused on soliton generation in TDF lasers, overlooking the switching and transformation between solitons in various states. This paper investigates the switching and transformation of multi-state solitons in TDF lasers based on nonlinear polarization rotation. By properly adjusting the pump power and polarization controller, we observe the switching and transformation between conventional soliton and bound state soliton, between soliton clusters and dual-wavelength soliton. The results were achieved using a simple structure (utilizing only one polarization controller) that exhibited superior repeatability and simplicity compared to a complex configuration (two polarization controllers). The experimental observation of the switching and transformation of multi-state solitons not only provides a deeper understanding of the dynamics of solitons in TDF lasers but also contributes to the design of multifunctional fiber lasers. This is significant for promoting the application of 2 µm fiber lasers.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"88 ","pages":"Article 103991"},"PeriodicalIF":2.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.yofte.2024.103960
Li Zhao , Wei Xun , Taiming Zhang , Shicong Wang
Transceiver sampling frequency offset (SFO) due to imperfections is one of the major factors restricting the transmission performance of the optical fiber coherent systems, especially when signals with high baud rate and therefore requiring higher sampling frequency of sampling devices like DACs or ADCs. In single-carrier signals transmission system, although adaptive clock recovery methods like Gardener or Godard method can compensate sampling error, when SFO is large enough so that one-frame length samples can accumulate to approximate one sample or above, the clock recovery will directly fail due to an extra sample is added or missed. The research of this issue for single-carrier signal is still rare. In this paper, we propose to use a digital interpolation method for single-carrier QAM signals for SFO compensation. The effectiveness of the proposed method is verified by a 32-GBaud 16-QAM dual-polarization 80-km SSMF optical coherent transmission experiment. The experimental results show that with proposed method, up to at least 1000-ppm SFO can be almost compensated to the bit error rate (BER) level as if without SFO. Besides, when using the proposed method, the required optical signal-to-noise ratio (OSNR) can be reduced by about 7 dB to achieve the BER level without SFO.
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