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:
May. 25, 2021
Filed:
Aug. 22, 2017
Hitachi High-technologies Corporation, Tokyo, JP;
Hitachi High-Technologies Corporation, Tokyo, JP;
Abstract
In an is-TPG method in which lasers having two different wavelengths are used to generate a wavelength-variable far-infrared light, a far-infrared light (TPG light) having an unstable output at a broad wavelength is also slightly generated at the same time with only one laser light. The generated is-TPG and the TPG light are converted, after passing through a specimen, to near-infrared light inside a nonlinear optical crystal for detection and are observed by a detector. The signal light output of the is-TPG light becomes unstable due to the TPG light. According to the present invention, the TPG light is removed by means of a slit and the like (filter) immediately before the specimen and is not introduced into the nonlinear optical crystal for detection. At this time, by using a change in the emission direction when the frequency of the is TPG light is changed, the filter is moved in accordance with the frequency so that only the is-TPG light passes therethrough (see FIG.C).