Investigation intensity response of distributed-feedback fiber laser to external acoustic excitation

The intensity response of distributed-feedback (DFB) fiber laser to external acoustic excitation has been investigated. On that basis, an intensity modulated sensing system based on DFB fiber laser has been constructed. Acoustic pressure sensitivity of the intensity-type sensor at frequencies ranging from 800 Hz to 9 kHz has been obtained by experiments for the first time to the authors’ knowledge. In addition, intensity response property of DFB fiber laser to external acoustic excitation with different pump power has been analyzed. We conclude that the signal power increases with the pump drive current of 980 nm laser diode (LD), and yet the ratios of signal power to DFB fiber laser power decrease. It confirms that the anti-interference performance of DFB fiber laser to fixed external acoustic interference becomes stronger with the increasing current of pump source, and this conclusion is beneficial to the investigation of wavelength demodulated sensors. F ilt e re d s ig n a l p o w e r, μ W 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 0.5 1.0 1.5 2.0 2.5 Signal intensity, V 1 kHz (a) 2 kHz (b) 3 kHz (c) Intensity response variation of the intensity-type sensor c ⃝ 2012 by Astro, Ltd. Investigation intensity response of distributed-feedback fiber laser to external acoustic excitation P.P. Wang, 1 J. Chang, 1,∗ C.G. Zhu, 1 W.J. Wang, 1 Y.J. Zhao, 1,2 X.L. Zhang, 2 G.D. Peng, 2,3 G.P. Lv, 1 X.Z. Liu, 2 and H. Wang 1 1 School of Information Science and Engineering, Shandong University, Jinan 250100, China 2 Laser Institute of Shandong Academy of Science, Jinan 250014, China 3 Photonics & Optical Communications Group, School of Electrical Engineering & Telecommunications, University of New South Wales, Sydney 2052, Australia Received: 2 April 2012, Accepted: 25 April 2012 Published online: 11 June 2012