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:
Apr. 08, 1997
Filed:
Jun. 13, 1995
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
The present invention comprises a compound cavity in which a vertical-cavity surface-emitting laser and external mirror are combined, and the change in intensity of a laser beam or in mirror loss is detected by the detection unit. The detection unit includes a photodetector for directly detecting a variation in intensity of a laser beam, and PN junction potential difference detecting device for detecting a variation in mirror loss created due to a relative displacement between the external mirror and the vertical-cavity surface-emitting laser, based on a change in carrier density within the surface-emitting laser. The phase of the laser beam returning from the external mirror is determined by a relative displacement between the external mirror and the vertical-cavity surface-emitting laser, and the laser beam output varies at a period of a displacement amount corresponding to 1/2 of the wavelength of the laser beam. Such a displacement amount is calculated by the counting device and the operation device.