The eigen-oscillation mode of the Nd:YAP cw laser has been analysed. The influence of thermal effects arising from the pumping process on the output character of the 1. 3414 mu m Nd:YAP cw laser has been discussed. The crack problem of the reflective film at a 1. 34 mu m dielectric mirror has been solved. Based on the aforementioned work, we have been able to achieve an 82. 8 W laser output at 1. 3414 mu m with a nearly polarized beam from a 5. 8 mm diameter by 111 mm Nd:YAP rod.