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. 01, 1981
Filed:
Feb. 29, 1980
Chandra K Patel, Summit, NJ (US);
Andrew C Tam, Sunnyvale, CA (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
Method and apparatus for high-sensitivity (.alpha..ltorsim.10.sup.-6 cm.sup.-1) optoacoustic (OA) spectroscopy of substantially transparent bulk condensed matter. Part of the sample to be investigated is irradiated by pulses of radiation, typically from a pulsed dye laser. The small amount of energy absorbed by the sample causes thermal expansion of the irradiated region, resulting in cylindrical stress waves being radiated from that region. These stress waves can be observed with appropriate detection means at a location remote from the source. The method is applicable to essentially transparent liquids, and solids, and to absorptive solids suspended in liquids, and the like. Possible choices of probe radiation are not only the conventional ones of visible, near UV, and near infrared electromagnetic radiation, but also, for instance, .gamma.-rays, x-rays, vacuum UV, and far infrared. Two conditions are shown to exist that relate pulse duration, beam size, and various material parameters, observation of which results in optimization of the sensitivity of the method, and the sensitivity is typically highest for pulses having duration of about 10.sup.-7 sec-10.sup.-4 sec.