Noise Characteristics for Random Fiber Lasers with Rayleigh Distributed Feedback

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Title: Noise Characteristics for Random Fiber Lasers with Rayleigh Distributed Feedback
Authors: Saxena, Bhavaye
Date: 2014
Abstract: Frequency and intensity noise are characterized for Erbium-Doped Fiber and Brillouin random lasers based on Rayleigh distributed feedback mechanism. We propose a theoretical model for the frequency noise of an Er-doped fiber random lasers using the property of random phase modulations from multiple scattering points in ultra-long fibers. We find that the Rayleigh feedback suppresses the noise at higher frequencies by introducing a Lorentzian envelope over the thermal frequency noise of a long fiber cavity. The theoretical model and measured frequency noise agree quantitatively with two fitting parameters. A similar model, which also includes additional acoustic fluctuations and a distributed gain profile in the fiber, has been speculated for the Brillouin random laser. These random laser exhibits a frequency noise level of < 6 Hz^2/Hz at 2 kHz, which is lower than what is found in conventional narrow-linewidth EDF fiber lasers and Nonplanar Ring Laser oscillators (NPRO) by a factor of 166 and 2 respectively.
URL: http://hdl.handle.net/10393/31766
http://dx.doi.org/10.20381/ruor-6615
CollectionThèses, 2011 - // Theses, 2011 -
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