Title:
SECONDARY HIGHER HARMONIC GENERATOR AND PICKUP FOR OPTICAL RECORDING MEDIUM
Document Type and Number:
Japanese Patent JPH04256932
Kind Code:
A
Abstract:
PURPOSE:To improve the efficiency of conversion from omega light to 2omega light by generating and emitting 2omega light from a nonlinear optical material only in one direction, to miniaturize a device and to reduce the cost of the device by eliminating the need for a large-sized, expensive optical isolator such as a Faraday rotator interposed conventionally between a light source for a fundamental wave and an external resonator. CONSTITUTION:The crystal axes of two lambda/4 plates 9A and 9B arranged in the external resonator by holding KNbO3 crystal 10 therebetween are slanted at 45 deg. to the polarizing direction of the omega light and then the polarization states of the omega light in the external resonator on its going and return ways intersects orthogonally with each other. The phase matching of the KNbO3 crystal 10 is realized only when the polarizing direction of the omega light is parallel to the crystal axis (b) and the 2omega light is emitted in a forwarding direction at this time. The 2omega light is not generated in the opposite returning way direction and the efficiency of conversion from the omega light to the 2omega light is improved.
Inventors:
FUJINO YOUSUKE
Application Number:
JP3918691A
Publication Date:
September 11, 1992
Filing Date:
February 08, 1991
Export Citation:
Assignee:
ASAHI GLASS CO LTD
International Classes:
G02F1/37; G11B7/135; H01S3/109; (IPC1-7): G02F1/37; G11B7/135