Tm:Ho:YLF Amplifiers at 2.049μm with a Tm:Ho:GdVO₄ Oscillator

We report cw diode-pumped cryogenic Tm:Ho:YLF amplifiers at 2.049μm with a Tm:Ho:GdVO₄ oscillator. Not only the single- and double-pass, but also the single- and double-end pump amplifiers with a 10-mm-length medium are compared. A measured maximum small-gain coefficient of 1.3cm^-1 is achieved for the double-pass and double-end pump amplifier. The maximum extracted power of 8.5W, the gain of 3.2 and extracted efficiency of 32% have been obtained with an input signal power of 3.9W. The difference of the hosts in the oscillator and amplifier has little influence on the characteristic of the amplifier output. Additionally, the extracted efficiency of the quasi-continuous-wave amplifier with a repetition rate of 10kHz is the same as the cw one.