Tuning room temperature noncritical phase matching of LiNbO/sub 3/ in the crystal growth process

Summary form only given. Noncritical type I birefringent phase matching for infrared-to-visible nonlinear frequency conversion in the blue-green region of the spectrum, requires heating LiNbO/sub 3/ congruent crystals very frequently to temperatures in excess of 100/spl deg/C. We have obtained accurate control of the room temperature fundamental wavelength in noncritical type I second harmonic generation (SHG) in LiNbO/sub 3/ crystals by adding a controlled concentration of K/sub 2/O to the congruent melt in a Czochralski LiNbO/sub 3/ crystal growth process.