摘要
The self-frequency doubling laser performance of Nd:GdCOB crystal cut in phase-matching direction(θ=66.3°,Ф=134.4°)was compared with the crystal cut in the direction of(θ=90°,Ф=46°).Results show that the former has a higher second-harmonic conversion efficiency than the latter.Using Ti:sapphire laser as pumping source,a maximum of 11.3mW of green light has been obtained with an incident power of 520mW.This corresponds to an optical-optical conversion efficiency of 2.2%.Laser threshold for self-frequency doubling operation is measured to be 1 mW.To our knowledge,this is the lowest threshold achieved so far.
