High power microsecond fiber laser at 1.5 μm

In this work, we demonstrate a single frequency, high power fiber-laser system, operating at 1550 nm, generating controllable rectangular-shape μ s pulses. In order to control the amplified spontaneous emission content, and overcome the undesirable pulse steepening during the amplification, a new method with two seed sources operating at 1550 nm and 1560 nm are used in this system. The output power is about 35 W in CW mode, and the peak power is around 32 W in the pulsed mode. The repetition rate of the system is tunable between 50 Hz to 10 kHz, and the pulse duration is adjustable from 10 μ s to 100 μ s, with all on the fly electronically configurable design. The system demonstrates excellent long and short time stability, as well as spectral and spatial beam quality.