Abstract

The developement of compact blue-green laser sources by frequency conversion is being energetically done for mainly high density optical memories. In Japan, the bulk type SHG devices using internal cavity resonant method with the combination of the Nd:YVO₄ microchip lasers and the nonlinear optical crystal KTP are popular because the system is simple, compact and easy to get transverse and londitudinal single mode and promising for practical devices. The present status and the problems for practical use of bulk type SHG devices using Nd:YVO₄, NYAB, organic nonlinear crystals and other crystals, which have being developed in Japan will be presented.

© 1993 Optical Society of America