GROWING OF WAVELENGTH-CONVERTING CRYSTAL AND CRYSTAL PREPARED THEREFROM

摘要

PROBLEM TO BE SOLVED: To prevent loss threshold of crystal from lowering without taking minute scattering bodies in crystal or without producing permeation loss of incident light and SHG light. SOLUTION: In this method for growing a wavelength-converting crystal by using a seed crystal 10 cut out in a specific phase matching direction, dried gas having <=10% relative humidity is made to flow into a growing furnace 20 during growth so that the dried gas strikes melt 21a. Specifically, the wavelength-converting crystal is lithium tetraborate and the seed crystal is cut out in phase matching direction inclined by 74±5 degree from (c) axis and grown into the wavelength converting crystal, which method is suitable for a Czochralski method using 5 times wave of Nd:YA laser. The dried gas is preferably dried air, dried argon or dried nitrogen.