Ho:YAP laser intra-cavity pumped by a diode-pumped Tm:YAP laser

We firstly demonstrated an obtainable Ho:YAP laser intra-cavity pumped by a diode-pumped Tm:YAP laser. A common 792 nm AlGaAs fiber coupled laser diode was used to pump the a-cut Tm:YAP crystal. In the Tm laser experiment, a maximum output power of 1.9 W at 1958.4 nm was obtained, corresponding to a slope efficiency of 12.1 %. In the Ho laser experiment, a maximum output power of 1.1 W at 2118.2 nm was obtained with a slope efficiency of 8.9% for 21.9 W diode incident pump power on the Tm:YAP crystal. At the maximum output power of the Ho laser, beam quality factor (M2) was measured to be 1.79 and 1.72 in the horizontal and vertical directions, respectively. Further improvement in the performances of the current Ho:YAP laser is predictable via direct producing a more compact gain module by adhesive-free bonding of Ho:YAP to Tm:YAP crystals.