Multi-wavelength Erbium-doped Fiber Laser Based On Stimulated Brillouin Scattering

For produce a larger number of laser wavelength by a fiber laser that as a result of the mutual interactions among the linear gain of erbium-doped fiber and fiber nonlinear stimulated Brillouin scattering gain.Multi-wavelength laser sources are of great interest in optical sensing, optical spectroscopy, microwave signal processing, and high capacity WDM communications. The main object of this paper is a multiwavelength Brillouin-erbium fiber laser based on stimulated Brillouin scattering.We first demonstrate a multiwavelength Brillouin-erbium fiber laser with double-Brillouin-frequency spacing. The wider channel spacing is realized by circulating the odd-order Stokes signals in the Brillouin gain medium through a four-port circulator. The circulated odd-order Stokes signals are amplified by the Brillouin gain and thus produce even-order Stokes signals at the output. These signals are then amplified by erbium gain block to form a ring-cavity laser. Ten channels with 0.174nm spacing that are generated at 0.5mW Brillouin pump power and 150mW pump power at 1480nm can be tuned from 1556nm to 1564nm. The minimum optical signal-to-noise ratio of the generated output channels is 30 dB with maximum power fluctuations of±0.5dB.Then a spacing-adjustable multiwavelength fiber laser based on self-excited stimulated Brillouin scattering without external Brillouin pump has been proposed and demonstrated. The nonlinear gain of self-excited stimulated Brillouin scattering can suppress mode competition induced by homogeneous broadening of erbium-doped fiber. With the use of a birefringence fiber loop filter, the wavelength spacing can be adjusted by changing the length of the used birefringence fiber, which makes the laser more flexible. Multiwavelength output with adjustable spectral spacing from 0.8nm to 0.076 nm has been experimentally obtained. And the wavelength number increases as the wavelength spacing decreases.