Tunable multiwavelength SOA fiber laser with ultra-narrow wavelength spacing based on nonlinear polarization rotation

Zuxing Zhang,Jintong Lin,Jian Wu,Xiaobin Hong,Kun Xu

doi:10.1364/oe.17.017200

Abstract

A tunable multiwavelength fiber laser with ultra-narrow wavelength spacing and large wavelength number using a semiconductor optical amplifier (SOA) has been demonstrated. Intensity-dependent transmission induced by nonlinear polarization rotation in the SOA accounts for stable multiwavelength operation with wavelength spacing less than the homogenous broadening linewidth of the SOA. Stable multiwavelength lasing with wavelength spacing as small as 0.08 nm and wavelength number up to 126 is achieved at room temperature. Moreover, wavelength tuning of 20.2 nm is implemented via polarization tuning.

Highlights

Multiwavelength fiber lasers have been extensively investigated for their potential applications in wavelength-division-multiplexing (WDM) communication systems [1], optical fiber sensors [2], optical instrument testing [3], and microwave photonics [4]
Due to the homogeneous line broadening of the erbiumdoped fiber (EDF) at room temperature, the fiber lasers based on EDF often suffer from strong mode competition and unstable multiwavelength lasing at room temperature
In order to validate the mechanism of the multiwavelength generation, we replace the polarization-dependent isolator (PDI) with a polarization-insensitive isolator

Summary

Introduction

Multiwavelength fiber lasers have been extensively investigated for their potential applications in wavelength-division-multiplexing (WDM) communication systems [1], optical fiber sensors [2], optical instrument testing [3], and microwave photonics [4]. A range of approaches have been put forward to solve this problem, such as cooling EDF to liquid-nitrogen temperature, utilizing four-wave mixing effect or inhomogeneous loss mechanism by using highly-nonlinear fiber, adding a frequency shifter or phase modulator, using nonlinear gain of cascaded stimulated Brillouin scattering or stimulated Raman scattering, and so on. All these inevitably add excess complexity and cost to these lasers. The effect of the SOA driving current on the performance of the multiwavelength laser is experimentally investigated

Experiment setup and operation principle

Results and discussion

Conclusion