公开(公告)号：US09664561B2

公开(公告)日：2017-05-30

申请号：US14896556

申请日：2014-06-04

Applicant: The Board of Regents of The University of Texas System

Inventor： Philip Varghese ,  Manfred Fink

IPC: G01J3/44 ,  G01J3/02 ,  G01J3/12

CPC classification number: G01J3/0205 ,  G01J3/0208 ,  G01J3/0264 ,  G01J3/4412 ,  G01J2003/1213

Abstract: Raman scattering, while a powerful and versatile technique, relies of the detection of weak signals. Detecting the signal can be difficult if there is interference, especially if the interference comes from scattered stray light of the laser used to generate the Raman signal. Described here is a frequency modulation technique in combination with heterodyne detection that simultaneously rejects interference from ambient light as well as from scattered stray laser light. This provides a means to detect Raman signal and discriminate against scattered light without using an expensive and bulky spectrometer.