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:
Apr. 02, 1985
Filed:
Jun. 03, 1982
Robert T Menzies, Pasadena, CA (US);
Charles W Rutledge, Temple City, CA (US);
Abstract
A system for remote absorption spectroscopy of trace species using a diode laser (14) tunable over a useful spectral region of 50 to 200 cm.sup.-1 by control of diode laser temperature over range from 15.degree. K. to 100.degree. K., and tunable over a smaller region of typically 0.1 to 10 cm.sup.-1 by control of the diode laser current over a range from 0 to 2 amps. Diode laser temperature and current set points are transmitted to the instrument in digital form and stored in memory (32) for retrieval under control of a microprocessor (28) during measurements. The laser diode current is determined by a digital-to-analog converter (62) through a field-effect transistor (Q.sub.1) for a high degree of ambient temperature stability, while the laser diode temperature is determined by set points entered into a digital-to-analog converter (64) under control of the microprocessor. Temperature of the laser diode is sensed by a sensor diode (18) to provide negative feedback to the temperature control circuit that responds to the temperature control digital-to-analog converter (64).