skip to main content

SciTech ConnectSciTech Connect

Title: Raman signal enhancement by multiple beam excitation and its application for the detection of chemicals

In a typical Raman based sensor, a single laser beam is used for exciting the sample and the backscattered or forward scattered light is collected using collection optics and is analyzed by a spectrometer. We have investigated that by means of exciting the sample with multiple beams, i.e., by dividing the same input power of the single beam into two or three or more beams and exciting the sample from different angles, the Raman signal enhances significantly. Due to the presence of multiple beams passing through the same volume of the sample, an interference pattern is formed and the volume of interaction of excitation beams with the sample increases. By means of this geometry, the enhancement in the Raman signal is observed and it was found that the signal strength increases linearly with the increase in number of excitation beams. Experimental results of this scheme for excitation of the samples are reported for explosive detection at a standoff distance.
Authors:
 [1] ;  [2] ; ;  [3] ; ;  [1]
  1. Laser Science and Technology Centre, Metcalfe House, Delhi 110054 (India)
  2. (India)
  3. Department of Physics, Indian Institute of Technology, Hauz Khas, New Delhi 110016 (India)
Publication Date:
OSTI Identifier:
22489190
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 9; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BEAMS; DETECTION; DISTANCE; EXCITATION; EXPLOSIVES; GEOMETRY; SENSORS; SIGNALS; SPECTROMETERS; VISIBLE RADIATION