Near diffraction limit 2.68 μm laser is obtained by intracavity KTP optical parametric oscillation (OPO) pumped by a 1064 nm laser.The experimental results are analyzed in detail.The pump source is an acousto-optical Q-switched Nd:YAG laser,and the OPO is doubly resonated.Two identical KTP crystals are placed with opposite optical axis to compensate the walk-off effect.The crystals are cut as φ=0°,θ=62° to generate 2.7 μm laser.To utilize the large effective nonlinear coefficient,the phase-matching is based on typeⅡ (o→o+e).When the pump power of the 808 nm laser diode is 330 W with a repetition rate of 7 kHz,an average output power of 7.6 W at 2.68 μm is obtained.The output power of the corresponding signal laser of 1.765 μm is about 14 W and the beam quality factor M2 of 2.68 μm laser is less than 1.6.