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:
Aug. 06, 1996
Filed:
Feb. 15, 1995
Toshiyuki Takeda, Tokyo, JP;
Ando Electric Co., Ltd., Tokyo, JP;
Abstract
In a variable wavelength light source, a light source emits coherent light, a first optical branching device branches light emitted from the light source, a frequency control circuit controls in frequency a signal generator, an optical phase modulator subjects one of the branched light to phase modulation when the signal generator sends a modulation signal thereto, a variable wavelength light source emits coherent light having a variable frequency, the coherent light is branched by a second optical branching device, an optical coupler combines the output of the second optical branching device with that of the optical phase modulator, the combined light is detected by a light detector, a phase comparator compares the output of the light detector with that of the signal generator to convert the phase difference therebetween into voltage and outputs the same, which is limited in bandwidth by a low-pass filter and is outputted to the variable wavelength light source. As a result, it is possible to provide a variable wavelength light source wherein the frequency difference between the light source and the variable wavelength light source can be varied over a wide range.