Random-lasing-based distributed fiber-optic amplification
ABSTRACT The gain and noise characteristics of distributed Raman amplification (DRA) based on random fiber laser (RFL) (including forward and backward random laser pumping) have been experimentally investigated through comparison with conventional bi-directional 1st-order and 2nd-order pumping. The results show that, the forward random laser pumping exhibits larger averaged gain and gain fluctuation while the backward random laser pumping has lower averaged gain and nonlinear impairment under the same signal input power and on-off gain. The effective noise figure (ENF) of the forward random laser pumping is lower than that of the bi-directional 1st-order pumping by ~2.3dB, and lower than that of bi-directional 2nd-order pumping by ~1.3dB at transparency transmission, respectively. The results also show that the spectra and power of RFL are uniquely insensitive to environmental temperature variation, unlike all the other lasers. Therefore, random-lasing-based distributed fiber-optic amplification could offer low-noise and stable DRA for long-distance transmission.
Full-textDOI: · Available from: Wei Li Zhang, Aug 26, 2014
Conference Paper: 142.2km BOTDA based on ultra-long fiber laser with a ring cavity[Show abstract] [Hide abstract]
ABSTRACT: A novel distributed Raman amplification (DRA) scheme based on ultra-long fiber laser (UL-FL) pumping with a ring cavity rather than a linear cavity is proposed and demonstrated, for the first time. As a typical application of the proposed configuration, ultra-long-distance distributed sensing with Brillouin optical time-domain analysis (BOTDA) over 142.2km fiber with 5m spatial resolution and ± 1.5℃ temperature uncertainty is achieved, without any repeater, for the first time. The key point for the significant performance improvement is the system could offer both of uniform gain distribution and considerably suppressed pump-probe relative intensity noise (RIN) transfer, by optimized design of system structure and parameters.Asia Pacific Optical Sensors Conference 2013; 10/2013
IEEE Journal of Selected Topics in Quantum Electronics 01/2015; 21(1):10-15. DOI:10.1109/JSTQE.2014.2344293 · 3.47 Impact Factor
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ABSTRACT: In this letter, we numerically study and experimentally achieve a low-threshold, high-efficiency random fiber laser, featuring a linear output as well. The lasing cavity incorporates a section of standard single-mode fiber and a band-selective point reflector placed at the far end of the fiber. The numerical result indicates that most energy is further pushed toward the pump side comparing with the open cavity scheme, producing a high-efficiency output. Then, we analyze the dependence of threshold and slope efficiency on cavity length and pumping wavelength. Most importantly, shorter cavity length would yield higher efficiency, and for different pumping wavelengths, there will be different cavity lengths corresponding to the lowest lasing threshold. Finally, we deliberately choose the parameters and experimentally achieve an 1145-nm random fiber laser with 7.13-W output and >90% slope efficiency (with 10-W pump), while the slope efficiency is almost constant above the 2-W lasing threshold. This letter provides a comprehensive guideline for designing such random fiber lasers with tailored performance.IEEE Photonics Technology Letters 11/2014; 27(3):319-322. DOI:10.1109/LPT.2014.2370644 · 2.18 Impact Factor