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:
Mar. 25, 1997
Filed:
Jan. 04, 1995
Daniel A Cohen, Goleta, CA (US);
The Regents of the University of California, Oakland, CA (US);
Abstract
A structure for stabilizing the wavelength and output power of uncooled diode semiconductor lasers using stress caused by differential expansion to counteract the effects of temperature fluctuation is realized by restraining the thermal expansion of the active region. The thermal expansion is restrained first by encapsulating the active region of the laser within a low expansion cap, and second, by applying stress to the active region by means of a high thermal expansion stress element mechanically coupled to the active region and restrained within the low expansion cap. As the temperature of the laser increases and it would normally attempt to expand, the stress element expands to even a greater degree with the combination of the active region and stress element both being contained within the low thermal expansion cap. The result is that physical thermal expansion of the active region is substantially eliminated or reduced and it operates under higher internal pressure. The structure for counteracting the effects of thermal expansion in active regions is applicable not only to lasers but all optoelectronic devices, to semiconductor devices, and in general, to any device having a energy band gap or any other parameter of operation dependant on thermal expansion.