WAVELENGTH CONVERTING DEVICE

摘要

PROBLEM TO BE SOLVED: To achieve high-efficiency and low-noise wavelength conversion without poling of a crystal and allow switching and modulating by an electric field of a converted light. SOLUTION: A KLTN crystal 4 is a plate having a thickness of 0.5 mm that both sides are optically polished, has electrodes that gold is deposited and provided in an entrance plane, and is connected from the electrodes to a DC power supply by using copper wires. The crystal material is the crystal having a composition of KTa1-x Nbx O3 and/or K1-y Liy Ta1-x Nbx O3 . A fundamental wave generated by a fundamental wave generating apparatus 1 uses a light of 1.55μm which is a differential frequency between a Q switch laser of Nd: YAG and an excimer laser, controls a polarized wave in a parallel direction to the electric field by using a polarizer 2, and enters between the electrodes of the KLTN crystal 4. The KLTN crystal 4 rotates a direction of the electric field on an axis. A part of a generated SHG light having the same polarized direction as that of an incident light enters into a photomultiplier 8 through a polarizer 7.