Use of Simple Octa-Ring Configuration for Tunable Erbium Laser With Single-Mode Output

Abstract

In this paper, an erbium-doped fiber (EDF) octa-ring laser system with continuous-wave (CW) tunability and stable single-longitudinal-mode (SLM) output is presented and investigated. The octa-ring configuration can cause a mode-filter operation based on the Vernier effect for dense side-mode suppression and gain extension. Therefore, the available wavelength-tuning bandwidth of the laser can be achieved from 1519.0 to 1575.0 nm by utilizing conventional C-band EDF based gain-medium. Moreover, the output power, output stability, optical signal to noise ratio (OSNR) and laser linewidth of the demonstrated EDF laser are also executed and discussed.INDEX TERMS Erbium-doped fiber (EDF), fiber laser, tunability, single-longitudinal-mode (SLM), octa-ring.

High-Performance Fiber Ring Laser Based on Polarization Space Parity-Time Symmetry Breaking

“…Consequently, by directly using conventional optical filters as wavelength selection elements for laser oscillators, it is challenging to achieve single-mode outputs. To overcome this challenge, common techniques for single-mode selection in fiber ring lasers include compound rings with Vernier effects [1][2][3][4][5], saturable absorbers [6][7][8][9], cascaded microfiber knots [10], whispering gallery mode resonator [11], phase-shifted fiber Bragg gratings [12], and dynamic gratings [13,14] to establish narrow linewidth filters. However, these methods often require complex cavity structures and fine parameter tuning.…”