Wavelength-spacing switchable multiwavelength fiber lasers based on nonlinear polarization rotation with cascaded birefringence fibers

Abstract

A wavelength-spacing switchable multiwavelength erbium-doped fiber lasers incorporating a highly nonlinear fiber (HNLF) based on nonlinear polarization rotation (NPR) has been demonstrated. The intensity-dependent transmission effect originating from NPR ensures room-temperature multi-wavelength lasing, which is further self-stabilized by the four-wave mixing in the HNF. Moreover, the equivalent Lyot birefringence fiber filter with two cascaded birefringence fibers makes the wavelength spacing switchable depending on the effective length of the birefringence fiber. The experimentally obtained multiwavelength outputs agree well with the simulation filter transmission spectra.

Keywords:

• fiber laser
• multiwavelength
• erbium-doped fiber
• nonlinear polarization rotation

Acknowledgements

This work is supported by the National Natural Science Foundation of China (60807014, 60967002), Open Fund of Key Laboratory of Information Photonics and Optical Communications, the Natural Science Foundation of Jiangxi province (2008GQS0050).