Second-harmonic generation of 405-nm light using periodically poled ${KT}i{OPO}_4$ pumped by external-cavity laser diode with double grating feedback
A frequency-doubled laser diode system for generation of blue-UV light is described. The system is based on an external-cavity high-power laser diode with double feedback from the zeroth and the first orders of a diffraction grating. Light at 405 nm is generated in a single-pass configuration using periodically poled KTiOPO4. We show that the double grating feedback improves the second harmonic co
