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Ju C, Liu N, Wang D, Wang D, Yu J, Qiu Y. Real-time demonstration of two-aperture coherent digital combining free-space optical transmission with a real-valued MIMO adaptive equalizer. OPTICS LETTERS 2024; 49:903-906. [PMID: 38359212 DOI: 10.1364/ol.511941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/13/2024] [Indexed: 02/17/2024]
Abstract
Compared with the single-aperture system, the multi-aperture coherent digital combining system has the technical advantage of the effective mitigation of deep fading under strong turbulence, ease of scalability, and potential higher collected optical power. However, the tricky problem of a multi-aperture system is to efficiently combine multiple branch signals with a static skew mismatch and with time-varying characteristics of received power scintillation. In this Letter, a real-valued massive array multiple-input multiple-output (MIMO) adaptive equalizer is proposed for the first time to our knowledge to realize multi-aperture channel equalization and combining, simultaneously. In the proof-of-principle system, the feasibility of the combining technique is verified based on a MIMO 4 × 2 equalizer in a 2.5-GBaud data rate QPSK modulation FPGA-based two-aperture coherent receiver with a dynamic turbulence simulator. The results show that no reduction in combining efficiency is observed under static turbulence conditions at the hard-decision forward error correction (HD-FEC) limit of 3.8 × 0-3, and combining efficiencies of 95% and 88% are obtained for the dynamic moderate and strong turbulence.
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Teng C, Min R, Zheng J, Deng S, Li M, Hou L, Yuan L. Intensity-Modulated Polymer Optical Fiber-Based Refractive Index Sensor: A Review. SENSORS 2021; 22:s22010081. [PMID: 35009621 PMCID: PMC8747346 DOI: 10.3390/s22010081] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/15/2021] [Accepted: 12/21/2021] [Indexed: 01/27/2023]
Abstract
The simple and highly sensitive measurement of the refractive index (RI) of liquids is critical for designing the optical instruments and important in biochemical sensing applications. Intensity modulation-based polymer optical fiber (POF) RI sensors have a lot of advantages including low cost, easy fabrication and operation, good flexibility, and working in the visible wavelength. In this review, recent developments of the intensity modulation POF-based RI sensors are summarized. The materials of the POF and the working principle of intensity modulation are introduced briefly. Moreover, the RI sensing performance of POF sensors with different structures including tapered, bent, and side-polished structures, among others, are presented in detail. Finally, the sensing performance for different structures of POF-based RI sensors are compared and discussed.
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Affiliation(s)
- Chuanxin Teng
- Guangxi Key Laboratory of Optoelectronic Information Processing, School of Optoelectronic Engineering, Guilin University of Electronic Technology, Guilin 541004, China; (S.D.); (M.L.); (L.Y.)
- Correspondence: (C.T.); (L.H.)
| | - Rui Min
- State Key Laboratory of Cognitive Neuroscience and Learning, Center for Cognition and Neuroergonomics, Beijing Normal University at Zhuhai, Zhuhai 519087, China;
| | - Jie Zheng
- State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China;
| | - Shijie Deng
- Guangxi Key Laboratory of Optoelectronic Information Processing, School of Optoelectronic Engineering, Guilin University of Electronic Technology, Guilin 541004, China; (S.D.); (M.L.); (L.Y.)
| | - Maosen Li
- Guangxi Key Laboratory of Optoelectronic Information Processing, School of Optoelectronic Engineering, Guilin University of Electronic Technology, Guilin 541004, China; (S.D.); (M.L.); (L.Y.)
| | - Li Hou
- State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
- Correspondence: (C.T.); (L.H.)
| | - Libo Yuan
- Guangxi Key Laboratory of Optoelectronic Information Processing, School of Optoelectronic Engineering, Guilin University of Electronic Technology, Guilin 541004, China; (S.D.); (M.L.); (L.Y.)
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Li J, Tong Z, Zhang W, Liu J. Research on multi-parameter characteristics of a PCF sensor modified by GO composite films. APPLIED OPTICS 2020; 59:9216-9224. [PMID: 33104633 DOI: 10.1364/ao.403064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/20/2020] [Indexed: 06/11/2023]
Abstract
We propose a photonic crystal fiber (PCF) sensor based on graphene oxide (GO) composite film modification to simultaneously measure the multi-parameter sensing characteristics of humidity, temperature, and glucose concentration. The GO-polyvinyl alcohol (PVA) composite film is used to measure the humidity-sensing characteristics of the sensor, and the glucose oxidase composite film is used to measure the sensing characteristics of the glucose concentration, respectively. Experiment results show that the sensitivities of the temperature of the GO-PVA coating structure are 0.037 nm/°C, 0.047 nm/°C, and 0.031 nm/°C; the sensitivities of humidity are 0.059 nm/%RH, 0.121 nm/%RH, and 0.047 nm/%RH; and the sensitivities of the glucose concentration of the GO-GOD coating structure are 0.028 nm/(g/L), 0.049 nm/(g/L), and 0.010 nm/(g/L) for three interference dips, respectively. The structure is simple to manufacture and can be used as a sensor for detecting multiple parameters. It can be widely used in biomedicine, environmental monitoring, and other fields.
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Refractive Index Sensor Based on Double Side-Polished U-Shaped Plastic Optical Fiber. SENSORS 2020; 20:s20185253. [PMID: 32937972 PMCID: PMC7570505 DOI: 10.3390/s20185253] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 02/08/2023]
Abstract
A U-shaped double-side polished plastic optical fiber (POF) is demonstrated as a liquid refractive index (RI) sensor. The refractive index of glycerinum solutions is identified by the intensity detection on the bending and evanescent wave loss change. Heat treatment and mechanical polishing are adopted to form the symmetrical side-polished POF probe. The processing parameters are experimentally optimized on the power transmittance. The sensitivity of 1541%/RIU (Refractive Index Unit) can be obtained with a resolution of 5.35 × 10−4 in the scope of 1.33–1.39. The favorable temperature characteristic is proved to offer stable RI sensing from 20 to 50 °C. This simple POF sensor has potentials in low-cost visible light intensity RI detection.
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Zhang Y, Hou Y, Liu W, Zhang H, Zhang Y, Zhang Z, Guo J, Liu J, Zhang L, Tan QL. A Cost-Effective Relative Humidity Sensor Based on Side Coupling Induction Technology. SENSORS 2017; 17:s17050944. [PMID: 28441321 PMCID: PMC5461068 DOI: 10.3390/s17050944] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 04/16/2017] [Accepted: 04/21/2017] [Indexed: 02/05/2023]
Abstract
A intensity-modulated optical fiber relative humidity (RH) sensor based on the side coupling induction technology (SCIT) is presented and experimentally demonstrated. The agarose gel and the twisted macro-bend coupling structure are first combined for RH sensing applications. The refractive index (RI) of the agarose gel increases with the increase of the RH and is in linear proportion from 20 to 80%RH. The side coupling power, which changes directly with the RI of the agarose gel, can strip the source noise from the sensor signal and improve the signal to noise ratio substantially. The experiment results show that the sensitivity of the proposed sensor increases while the bend radius decreases. When the bend radius is 8 mm, the sensor has a linear response from 40% to 80% RH with the sensitivity of 4.23 nW/% and the limit of detection of 0.70%. A higher sensitivity of 12.49 nW/% is achieved when RH raises from 80% to 90% and the limit of detection decreases to 0.55%. Furthermore, the proposed sensor is a low-cost solution, offering advantages of good reversibility, fast response time, and compensable temperature dependence.
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Affiliation(s)
- Yingzi Zhang
- Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
- Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
| | - Yulong Hou
- Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
- Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
| | - Wenyi Liu
- Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
- Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
| | - Huixin Zhang
- Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
- Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
| | - Yanjun Zhang
- Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
- Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
| | - Zhidong Zhang
- Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
- Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
| | - Jing Guo
- Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
- Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
| | - Jia Liu
- Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
- Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
| | - Liang Zhang
- Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
- Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
| | - Qiu-Lin Tan
- Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
- Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
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