- 标题
- 摘要
- 关键词
- 实验方案
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Passively Q-switched fiber laser tunable by Sagnac interferometer operation
摘要： In this paper, a stable passively Q-switched Erbium-doped fiber laser (EDFL) tunable by Sagnac interferometer operation was described by using a graphene oxide saturable absorber (SA) as a Q-switcher. The wavelength operation of the Q-switched EDFL was tunable from 1566.3 nm to 1559.3 nm by increasing the temperature of sagnac loop mirror (SLM) from 30 °C to 70 °C in the figure-of-eight laser configuration. At 1566.3 nm operation, by increasing the pump from the threshold power of 77.3 mW to 126.5 mW, the repetition rate can be increased from 30.7 kHz to 41.5 kHz while the pulse width was narrowed from 10.2 to 7.3 μs. The Q-switching threshold pump power increased with the increase of the temperature, which then shifted the operation to a shorter wavelength. However, the laser efficiency increased at a shorter wavelength operation. At 1561.4 nm operation, the maximum pulse energy of 20.5 nJ was obtained at 161.0 mW pump power.
关键词： Q-switching operation,Fiber lasers,Sagnac loop mirror,Temperature tuning
更新于2025-11-28 14:24:03
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Switchable dual-wavelength fiber laser based on a phase-shifted fiber Bragg grating combined with Mach-Zehnder interferometer and Sagnac loop
摘要： A switchable dual-wavelength erbium-doped fiber laser is proposed and demonstrated. It is based on the finer filter effect of phase-shifted fiber Bragg grating (PSFBG), combining with the compound interference filtering effect of Mach-Zehnder interferometer (MZI) and Sagnac loop. By adjusting the polarization controller (PC) and tuning the delay, the switchable single- and dual-wavelength fiber laser with tunable wavelength spacing can be obtained. As a result, the dual-wavelength spacing as small as 0.04 nm is achieved, the output wavelength is from 1555.580 nm to 1559.928 nm, and the side mode suppression ratio (SMSR) is larger than 40 dB. The maximum wavelength drift of single-wavelength is less than 0.033 nm, and the maximum fluctuation of dual-wavelength is less than 0.02 nm. The experimental results show that the proposed fiber laser has important applications, such as in high fineness dense wavelength division multiplexing (DWDM) systems and other similar fields.
关键词： Switchable dual-wavelength,Mach-Zehnder interferometer,Fiber laser,Sagnac loop,PSFBG
更新于2025-11-28 14:24:03
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All-polarization-maintaining dual-wavelength mode-locked fiber laser based on Sagnac loop filter
摘要： We demonstrate an all polarization-maintaining (PM) fiber based dual-wavelength mode-locked Er-fiber laser. A nonlinear amplifying loop mirror (NALM) with an intracavity nonreciprocal phase shifter is used for self-started mode-locking. A short segment of PM fiber is angle-spliced to the NALM, functioning as a PM Sagnac loop filter, thus enabling dual-wavelength mode-locking. The wavelength separation is solely determined by the angle-spliced PM fiber length. Stable dual-wavelength mode-locking operation is switchable between 1570/1581 nm and 1581/1594 nm. The two-color pulse trains oscillating in the same cavity have an inherent offset repetition rate of ~1 kHz owing to cavity dispersion, allowing future high precision dual-comb applications with a simple and robust configuration.
关键词： polarization-maintaining fiber,dual-comb applications,dual-wavelength mode-locked fiber laser,Sagnac loop filter
更新于2025-11-28 14:24:03
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Simultaneous measurement of temperature and refractive index based on microfiber Bragg Grating in Sagnac loop
摘要： In this paper, a simultaneous measurement system of temperature and refractive index (RI) is proposed and demonstrated. The dips in the output spectrum of the proposed sensor are formed by the micro?ber Bragg Grating (mFBG) and Sagnac loop. Due to di?erent interference mechanisms, the dual-parameter measurement is realized by mFBG and Sagnac loop with di?erent sensitivities to temperature and RI. Compared with the traditional Sagnac loop sensors, the proposed Sagnac loop with mFBG is much sensitive to surrounding RI. The results show that the temperature sensitivity is 0.033 nm/°C and ?0.015 dB/°C. And the RI sensitivity is 39.30 nm/RIU and 41.51 dB/RIU. The proposed sensor has a simple structure and great potential in biological and chemical ?elds.
关键词： Micro?ber Bragg Grating,Sagnac loop,Dual-parameter measurement
更新于2025-09-23 15:22:29
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Intensity-modulated Sagnac loop temperature sensor setup
摘要： In this article, the novel low-cost and simple intensity-modulated Sagnac loop based temperature sensor setup is presented. The sensor head consists of a short length of polarization-maintaining fiber (PMF), which is spliced to a single-mode fiber optic coupler. Due to the short section of PMF, the spectrum has wide separation between adjacent interferometer dips. This idea ensures that transmission of a broadband light source has different losses after propagation through Sagnac loop whether temperature changes and causes shift of interferometer dips. Therefore, tracking of wavelength shift of interferometer dip is not required in this setup as it relies on direct optical power measurement. Instead of using spectral analysis instruments, we present the novel intensity-modulated optical fiber temperature sensor based on Sagnac loop created of short section of PMF. This particular sensor was experimentally investigated for a temperature range of 25-50.5°C and exhibited the sensitivity of 0.066 mW/1°C with resolution of 0.34°C. The setup could be easily applied in order to create fiber optic sensor network for temperature monitoring.
关键词： Sagnac loop,fiber sensor,optical power measurement,temperature sensor,intensity-modulated sensor
更新于2025-09-19 17:15:36
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Switchable dual-wavelength mode-locked fiber laser using Saganc loop mirror
摘要： We report an all-fiber switchable dual-wavelength mode-locked laser using a Sagnac loop mirror. In this laser, the Sagnac loop mirror acts as a tunable periodic filter, in which the wavelength spacing is determined by the length of the polarization maintaining fiber. With appropriate pump power, the mode-locked fiber laser can operate in both the tunable single-wavelength mode locking regime and the dual-wavelength mode locking regime by properly setting the states of the polarization controllers. In the single-wavelength mode locking regime, the laser achieves continuously tunable wavelength range from ～1551 nm to ～1562 nm. In the dual-wavelength mode locking regime, the laser can emit two stable asynchronous pulse trains with the central wavelengths of 1561.4 nm and 1551.1 nm, respectively. Due to the net negative dispersion of the laser cavity, the mode-locked pulse trains with different central wavelengths have different group velocities leading to a repetition rate difference of ～530 Hz.
关键词： Tunable wavelength,Dual-wavelength,Sagnac loop mirror,Mode-locked fiber laser
更新于2025-09-19 17:13:59
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - A sensitivity enhanced Sagnac temperature sensor utilizing high order modes interference
摘要： A temperature sensor is proposed by splicing a section of thin polarization-maintaining fiber in a Sagnac loop. The temperature sensitivity is enhanced by higher-order modes interference and reaches up to 1.7 nm/(cid:31).
关键词： Thin polarization-maintaining fiber,Temperature sensor,higher-order modes interference,Sagnac loop
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Research on all-fiber deep sea pressure sensor
摘要： Theoretically analyzed and experimentally demonstrated an all-fiber pressure sensor based on a microfiber coupler combined SAGNAC loop. The work of this paper proves the usability of the structure in the deep sea environment.
关键词： deep sea pressure sensor,SAGNAC loop,All-fiber sensing,microfiber coupler
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Temperature and Salinity Sensing Experiment Based on Microfiber Coupler Combined SAGNAC Loop
摘要： A microfiber coupler conbined SAGNAC loop is fabricated temperature and salinity sensing experiment. The experimental results show that the sensitivity is high, and its dynamic range can meet the marine environment monitoring demand.
关键词： temperature sensing,salinity,SAGNAC loop,microfiber coupler
更新于2025-09-12 10:27:22
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[IEEE 2019 International Topical Meeting on Microwave Photonics (MWP) - Ottawa, ON, Canada (2019.10.7-2019.10.10)] 2019 International Topical Meeting on Microwave Photonics (MWP) - Phase Noise Performance of SILPLL based Opto-electronic Oscillator using Sagnac-loop PM-IM Convertor
摘要： Forced opto-electronic oscillators (OEO) are important component in future telecommunications and instrumentation systems. Most OEO are realized using intensity modulators (IM) with recent interest shifting to phase modulators (PM). A comprehensive analysis of Sagnac loop based OEO is presented, where phase is converted to intensity (PM-IM). This paper evaluates phase noise performance of SILPLL OEO in terms of Sagnac loop component errors and its impact on the PM-IM conversion. Results are presented for a 10 GHz SILPLL based OEO.
关键词： Phase modulator,Sagnac Loop,PM-IM conversion,Opto-electronic oscillators
更新于2025-09-12 10:27:22