Dysprosium-Doped Chalcogenide Master Oscillator Power Amplifier (MOPA) for Mid-IR Emission

The paper describes the design of a medium infrared fiber laser based on a dysprosium-doped chalcogenide glass Dy3+ : Ga5 Ge20Sb10S65. To obtain a high efficiency, the fiber laser is followed by an optical amplifier making use of residual pump power. The optimized optical source exploits a master oscillator power amplifier (MOPA) configuration. The MOPA pump and signal wavelengths are 1709 and 4384 nm, respectively. Spectroscopic parameters measured on preliminary samples of chalcogenide glasses are taken into account to fulfill realistic simulations. The MOPA emission is maximized by applying a particle swarm optimization approach. For an input pump power of 3 W, an output power of 637 mW can be obtained for optical fiber losses close to 1 dB m-1. The optimized MOPA configuration allows a laser efficiency larger than 21%