Blue light generation by intra-cavity frequency-doubling with a PPMgLN

We have obtained a 4.2 mum periodically domain inverted structure in a MgO:LiNbO3crystal, and developed a compact blue laser with the MgO doped periodically poled LiNbO3(PPMgLN). 240 mW at 456 nm was generated by intra-cavity frequency-doubling.