1760 nm Multi-Watt Broadband PM CW and Pulsed Tm-Doped Fiber Amplifier

We report the performance of CW and pulsed single-clad PM Tm-doped fiber amplifiers optimized for the wavelength band from 1760 to 1960 nm. For the CW regime, we have achieved output power levels as high as 3 W with a two-stage TDFA designed for operation at 1760 nm. Simulations indicate that this 3 W output power extends from 1760 nm to 1960 nm. OSNR values >55 dB in 0.1 nm are experimentally measured for the optimized two-stage TDFA. In the pulsed regime, we studied the performance of the amplifier with 50–100 ns input pulses and repetition rates from 100 kHz to 1 MHz. We studied in detail the evolution of the output pulse shape, first with square input, and then with shaped input pulses using an arbitrary waveform generator that resulted in an optimized square output pulse shape. Average output powers of 2 W, peak output powers of 20 W (10% duty cycle), and pulse energies of 1.6 μJ were achieved.