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:
Oct. 12, 2004
Filed:
May. 01, 2003
Barry G. Mattox, Orlando, FL (US);
Lockheed Martin Corporation, Bethesda, MD (US);
Abstract
A method and apparatus for accurately and precisely controlling the frequency (wavelength) and periodic frequency modulation of a laser are provided. An ADC (Analog to Digital Converter) is used to sample the output of a modified interferometer used as a delay line discriminator, and quadrature components of the sampled output are generated. An arctangent function (e.g., atan ) is applied to convert the quadrature components to a phase measure that is proportional to the laser frequency. Correlator circuits (e.g., cost-efficient correlator circuits) are provided to extract average frequency, modulation peak deviation, and modulation phase error signals. Control-loop feedback using the extracted signals is used to adjust the average frequency, modulation deviation, and modulation phase to respective set points.