The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 28, 1995
Filed:
Oct. 06, 1993
NEC Corporation, Tokyo, JP;
Abstract
An Er:YVO.sub.4 laser oscillator has an excitation light source constituted by a laser diode and a medium constituted by an Er:YVO.sub.4 crystal in which Er.sup.3+ ions are activators and YVO.sub.4 is a host material. The oscillation light is perpendicular or parallel to c-axis of the crystal. The laser operates in target wavelengths on energy transitions of the Er.sup.3+ ions, the target wavelengths being 510 nm to 590 nm, 840 nm to 870 nm, 970 nm to 1020 nm, and 1450 nm to 1700 nm. The crystal is coated with a TiO.sub.2 --SiO.sub.2 system high reflection mirror coating and a fluoride megnesium-zeolite system antireflection coating corresponding to the target wavelengths and a fluoride megnesium-zeolite system antireflection coating corresponding to the wavelength of the laser diode. These coatings together with an output mirror constitute a resonator. For manufacturing the crystal, Er.sub.2 O.sub.3, Y.sub.2 O.sub.3, and V.sub.2 O.sub.5 used as starting materials are subjected to a Czochralski growth process using a high frequency induction heating furnace with the direction of growth being in an a-axis. This is followed by a thermal treatment under a temperature in the neighborhood of a growth temperature or a thermal treatment in an oxygen atmosphere. It has been made possible to produce a single laser crystal of YVO.sub.4 with an improved quality and enhanced yield.