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:
Dec. 02, 1980
Filed:
Jun. 16, 1978
John M Holland, Shawsville, VA (US);
International Telephone and Telegraph Corporation, New York, NY (US);
Abstract
A laser stabilizing apparatus employs two feedback control loops. One control loop serves to monitor the light intensity output of the laser and provides an error output signal which is compared with a reference signal to develop a control signal that is integrated and used to control the output level of the laser diode during normal operation. In such operation, the laser diode is modulated according to an input signal which possesses a balanced duty factor. If the duty factor of this signal becomes imbalanced, a second control loop detects the imbalance and operates via the integrator to turn the laser diode off to thus prevent facet damage. The circuitry described operates at a substantial power saving due to the fact that there is no prebias current applied to the laser and hence, the laser operates between a conducting and nonconducting mode and under control of the above described loops.