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:
Jul. 09, 1996
Filed:
Sep. 21, 1994
Hiroshi Mori, Ohizumi-machi, JP;
Masatoshi Bendo, Gunma-ken, JP;
Advantest Corporation, Tokyo, JP;
Abstract
A measurement apparatus and method for evaluating a light emitting device automatically measures a carrier-noise ratio, an optical modulation index, and a relative intensity noise of the light emitting device, and graphically displays the resulted data. The measurement apparatus includes a photo detector for converting an input light signal from the light emitting device to an electric current, a DC amplifier for amplifying a DC component of the electric current, a first analog-to-digital convertor for digitizing the output of the DC amplifier, a RF amplifier for amplifying a high frequency component of the electric current, a detector for detecting the output of the RF amplifier, a second analog-to-digital convertor for digitizing the output of the detector, a controller for controlling sequences of automatic measuring operations, a display device for displaying the characteristics of the light emitting device.