Beating frequency tunable dual-wavelength erbium-doped fiber laser with one fiber Bragg grating

A tunable dual-wavelength erbium-doped fiber laser (EDFL) is proposed and demonstrated. By applying axial and lateral strain simultaneously on the fiber Bragg grating (FBG), the absolute wavelength and wavelength spacing of the EDFL can be tuned continuously. The FBG used included not only the FBG fabricated in standard single-mode fiber, but also the FBG in polarization-maintaining fiber. The experiment results are similar.

I. Introduction

Multiwavelength fiber lasers have attracted much interest in recent years because of their potential applications in wavelength-division-multiplexed (WDM) technique, fiber sensor system, and optical instrument testing [1]–[3]. Various techniques for the reduction of wavelength competition have been used to achieve stable multiwavelength oscillations. The wavelength competition originates from the homogeneous gain broadening of erbium-doped fiber (EDF) [2]. In order to overcome this limitation, approaches such as cooling the EDF to 77 K to make the gain medium inhomogeneous or polarization hole burning have been proposed [4], [5].