Ho:KLuW microchip laser intracavity pumped by a diode-pumped Tm:KLuW laser

摘要

A compact intracavity-pumped microchip Ho laser is realized using stacked Tm:KLuW/Ho:KLuW crystals pumped by a laser diode at 805 nm; both crystals are cut for light propagation along the N (g) optical indicatrix axis and emit with polarization along the N (m) axis. Maximum CW output power of 285 mW is achieved at a wavelength of 2080 nm for 5.6 W absorbed pump power in the Tm:KLuW crystal with a maximum slope efficiency of 8.3 %. Maximum total (Tm3+ and Ho3+ emission) output of 887 mW with a slope efficiency of 23 % is achieved. Laser operation is obtained in the 1867-1900 nm spectral range corresponding to the Tm emission, while Ho emits at 2078-2100 nm, depending on the output coupling. The microchip Ho laser generates a near-circular output beam with M (2) < 1.1. The compact laser setup with plane-plane cavity provides automatic mode-matching condition for the Tm and Ho laser modes.