3-channel Single-Longitude-Mode Tunable Fiber Laser by using a Digital-Micro-Mirror-Device Processor and Sub-ring Cavities

This A novel 3-channel single-longitudinal-mode (SLM) tunable erbium-doped fiber laser with sub-ring cavities based on a digital Opto-digital-micro-mirror device (Opto-DMD) processor is proposed and experimentally demonstrated. 3-channel tunable SLM lasing were obtained simultaneously by means of the Opto-DMD processor without any mechanically shift, which is the unique feature and innovative point of 3-channel laser. The DMD processor can select and couple any waveband from the gain spectrum of the EDFA into the main fiber ring, which can guarantee the multiple-channels laser output. Different short passive sub-ring cavities are inserted into the main ring cavity for each channel and serve as mode filters, to make SLM lasing. The experimental results demonstrate the side-mode-suppression-ration (SMSR) is about ~40 dB, and the output power is more than ~9.5 dBm in the operating range. The center wavelength and power fluctuations are below ~0.025 nm and ~0.06 dBm, respectively.