Dual-wavelength Raman Fiber Laser Research Articles

Frequency Down-Conversion of Dual-Wavelength Raman Fiber Laser in PPLN-Based Optical Parametric Oscillator

We report on frequency down-conversion of dual-wavelength (DW) Raman fiber laser in a periodically poled lithium niobate-based optical parametric oscillator. The DW pump source was fixed at 1060 and 1111 nm that was obtained based on stimulated Raman scattering effect by combining a home-made linearly polarized 1060-nm fiber laser and 137-m-long polarization-maintaining passive fiber. The total pump power went through three stages, in the latter two of which the 1111-nm wave appeared. In the entire experiment, the 1060-nm pump beam achieved parametric oscillation and generated 1626-nm signal beam and 3056-nm idler beam. The 1111-nm pump beam generated 3503-nm idler beam based on difference frequency generation (DFG) between itself and 1626-nm signal beam in the second stage. With power enhancement, it built independent parametric oscillation in the third stage and generated 1621-nm signal beam as well as 3530-nm idler beam. The DW idler power ranged from 3.94 to 7.78 W in the latter two stages. The power and efficiency characteristics in frequency conversion processes of 1060- and 1111-nm pump beams were also analyzed separately.

Interrogation of a Suspended-Core Fabry–Perot Temperature Sensor Through a Dual Wavelength Raman Fiber Laser

The interrogation of a Fabry-Perot cavity through a dual wavelength Raman fiber laser is reported. The proposed sensing system is based on the use of a dual wavelength Raman fiber laser to generate two quadrature phase-shifted signals that allow the recovery of the temperature change sensed by the Fabry-Perot interferometric cavity. The dual wavelength Raman fiber laser is based on fiber Bragg gratings combined with a distributed mirror. The Fabry-Perot cavity is fabricated by splicing a short length of a suspended-core microstructured fiber to a single mode fiber. The use of this sensing system allows a passive and accurate interrogation of the temperature, while taking advantage of the Rayleigh scattering growth as a distributed mirror in the laser.

Optimization of dual-wavelength cascaded Raman fiber lasers using an analytic approach

In this paper, an approximate analytical method is developed to solve the coupling equations which characterize the dual-wavelength cascaded Raman fiber laser with a low reflective fiber Bragg grating as the output reflector for intermediate Stokes radiation. Good agreement between analytical results and numerical simulation is demonstrated and accordingly optimization of the dual-wavelength Raman fiber laser can be discussed analytically. The results show that there exists a set of optimal length of Raman fiber and reflectivity of output fiber Bragg grating for the first and second Stokes radiations to maximize the output power while maintaining the output power of the first and second Stokes radiations equal.