Novel Technique to Discriminate Against Ambient and Scattered Laser Light in Raman Spectrometry

Physical Sciences : Physics

Available for licensing


  • Philip Varghese, Ph.D. , Aerospace Engineering and Engineering Mechanics
  • Manfred Fink, Ph.D. , Physics

Background/unmet need

Raman scattering, while a powerful and versatile technique, has 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. Modulating the laser beam intensity does not solve the problem, because the scattered stray light is modulated at the frequency of the signal. 

Invention Description

Researchers at The University of Texas at Austin use a frequency modulation technique in combination with heterodyne detection to reject interference from ambient light as well as from scattered stray laser light.


  • Increases detectability of the Raman signal
  • Lowers the detection threshold of compounds


    Provides a means to detect Raman signal and discriminate against scattered light without using an expensive and bulky spectrometer

Market potential/applications

Medical, industrial and environmental monitoring applications are being explored. 

Development Stage

Proof of concept

IP Status