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. 04, 1989
Filed:
May. 04, 1987
George A Tanton, Huntsville, AL (US);
John A Grisham, Huntsville, AL (US);
The United States of America as represented by the Secretary of the Army, Washington, DC (US);
Abstract
A sensitive infrared polarimeter that measures the amount of degree of rotation of the plane of polarization of plane polarized radiation after the radiation has passed through a wafer of cadmium sulfide. The wafer is placed in a relatively small magnetic field that is varied. Increased sensitivity is realized by using a chopping wheel to chop the laser beam, providing a reference frequency and by detecting the signals with a synchronous detector such as a lock-in amplifier to obtain high signal to noise ratios of the detected signal. The greater sensitivity of the high-sensitivity infrared polarimeter allows electronic carrier concentrations as low as 10.sup.15 cm.sup.-3 to be measured in cadmium sulfide with magnetic fields as low as 0.1 Tesla.