Light source device and optical pickup using light source device

Abstract

An SHG element has a semiconductor laser, and a laser resonator for exciting an oscillation line having a predetermined wavelength by making a light beam emitted from the semiconductor laser incident to the laser resonator. The laser resonator converts the wavelength on the oscillation line by a nonlinear optical crystal and emits SHG light having a converted wavelength. The laser resonator uses Nd:YVO.sub.4 as a laser medium for exciting the oscillation line having the predetermined wavelength. The semiconductor laser emits a light beam having power required to obtain the SHG light having predetermined power from the laser resonator when Nd:YVO.sub.4 is used as the laser medium of the laser resonator. A light source device has a semiconductor laser capable of directly modulating light; a wavelength converting section for emitting light having a short wavelength based on LD light from the semiconductor laser; and a device for superposing the LD light from the semiconductor laser on the light having a short wavelength to emit superposed light. An optical pickup uses this light source device.

Dependencies are inferred from the claim text.