Ho:YAG absorption cross sections from 1700 to 2200 nm at 83, 175, and 295 K.

We have obtained absorption spectroscopic cross sections as a function of wavelength for the laser material Ho:YAG at 295, 175, and 83 K, in the spectral range from 1700 to 2200 nm. The absorption range corresponds to (5)I8-(5)I7 transitions from the ground state to the first excited state amenable to direct pumping by laser diodes and Tm fiber lasers. The data allow a direct comparison of the absorption cross-section intensities and linewidths as temperature is lowered from room temperature to cryogenic temperatures.

201 W picosecond green laser using a mode-locked fiber laser driven cryogenic Yb:YAG amplifier system.

We have generated 201 W of green (514.5 nm) average power from a frequency-doubled picosecond cryogenic Yb:YAG laser system driven by a 50 MHz, 12.4 ps mode-locked Yb fiber laser producing 430 W of average power at 1029 nm, using direct pulse amplification.