Abstract

Segmented optical waveguides in KTiOPO₄ were coupled to single mode diode lasers for blue light generation using QPM. The KTP waveguide consists of an ~4 μ periodic domain-inverted array of Rb/Ba diffused and non-diffused areas. This grating produces a narrow Bragg peak in reflected light at a specific wavelength. The reflected light was used to lock the diode laser, forcing it to remain narrow-band even in the presence of reflected light from the end faces of the waveguide. Temperature tuning of the KTP brought the SHG peak into coincidence with the Bragg-locked laser, with 5 °C bandwidth. The blue power obtained at 422 nm was 0.3 mW for a 5 mm long waveguide, using 113 mW IR at the focusing objective, and with 39 mW IR emerging from the waveguide. This technique eliminates the need for an optical isolator between diode and waveguide.

© 1992 Optical Society of America