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. 28, 1993
Filed:
Mar. 30, 1992
George T Harvey, Princeton, NJ (US);
Linn F Mollenauer, Colts Neck, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
In a harmonically mode-locked laser, first (33) and second (34) optical beams are derived from the laser optical path which are directed, respectively, through first and second optical filters (37) having optical pass-bands (40, 41) that are displaced in frequency but which intersect at approximately the center frequency (f.sub.c) of operation of the laser. The free spectral range of a Fabry-Perot optical resonator (24) in the laser ring is deviated from a frequency exactly equal to the pulse repetition rate of the laser by a frequency (df) sufficient to permit changes in the length of the optical path to be manifested as changes in the wavelength of light transmitted along the optical path. Apparatus (39, 40, 42) for detecting the difference of intensity of light passing through the first and second filters can then be used to generate a signal proportional to the difference of intensity of such light for the purpose of adjusting, by length adjusting apparatus (43), the length of the optical path to compensate for spurious temperature-induced length variations.