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:
Jan. 17, 1995
Filed:
Jan. 26, 1994
Akio Ichikawa, Tokyo, JP;
Ando Electric Co., Ltd., Tokyo, JP;
Abstract
An optical phase locked loop circuit, which controls so that the optical frequency of the light 19A generated by the slave laser 19 has the offsetting factor to the optical frequency of the coherent light 11A generated by the master laser 11, corresponding to the frequency of the signal 16A generated by the signal generator 16, is provided with a LPF 1, an optical power controller 2 and a variable optical attenuator 3. Upon detecting the phase difference caused by the difference frequency between the light 19A and the coherent light 11A, the output control light 3A is obtained by transmitting the output control light 20B through the variable optical attenuator 3. The signal 13B proportional to the optical power of the output control light 3A is extracted by the LPF 1. The optical power of the light 3A is stabilized by using the optical power controller 2 and the variable optical attenuator 3 in order to vary the optical power attenuation in the light 20B corresponding to the extracted signal 13B.