Use of proper cavity loss for a stable single-longitudinal-mode erbium fiber laser

Abstract

A stable and selectable erbium-doped fiber (EDF) ring laser configuration with single-longitudinal-mode (SLM) output is proposed and demonstrated in this paper. In the proposed laser scheme, a proper cavity loss is utilized for significant suppression of the side mode. In the experiment, the different coupling ratios required to produce various cavity losses in the proposed fiber laser are analyzed. Here, to reach the wavelength selection, several fiber Bragg gratings (FBGs) and an optical tunable bandpass filter (OTBF) in the C-band range are employed for demonstration. In addition, the output performance with respect to stability and SLM in the proposed EDF ring laser are also investigated simultaneously.

An Erbium Fiber Laser With Single-Frequency Oscillation and Wavelength-Upconverted Output

“…In recent times, erbium-doped finer (EDF) based gain medium in the fiber laser systems have attracted more interests due to their valuable applications in the optical communication, wavelength-division-multiplexing (WDM) traffic, micro-wave photonic, fiber sensing, high resolution spectroscopy and instrument testing [1][2][3][4][5]. Furthermore, the homogeneous broadening gain medium of EDF and longer fiber loop in the fiber laser would bring the unstable multi-longitudinal-mode (MLM) and mode-hopping output [6,7]. Hence, in order to attain the single-longitudinal-mode (SLM) oscillation in the EDF based lasers, a number of techniques have been proposed and demonstrated, such as exploiting a unpumped EDF or graphene based saturable absorbers (SAs) [8,9], using the multiple-ring architectures [10,11], employing optical-injection loop design [12,13], applying Mach-Zehnder interferometer (MZI) structure [14,15], and utilizing the Rayleigh backscattering (RB) method [16,17].…”