A Refractive Index-Based Sensor for the Discrimination of Chlorinated Hydrocarbons from Groundwater.

Abstract

A refractive index-based sensor uses a light source and an optical fiber to direct an optical beam towards a sensor/ environment face at a specific angle. The sensor has a predetermined shape selected such that the light directed into the sensor will have a specific angle of incidence designed to detect a plurality of liquids. A second optical fiber carries the light reflected off the sensor/environment face to a photodetector. The optical beam will either be transmitted through or reflected off the sensor/environment face based upon the refractive indices of the sensor and the environment and upon the angle of incidence of the optical beam. The amount of light reflected is indicative of the refractive index of the material in a given area of the sensor/environment face and, thus, the type of material. By adjusting the angle at which the light is directed to the sensor/environment face, the photodetector response can be calibrated to identify the type of liquid present at the sensor/environment face.

Document Details

Document Type
Technical Report
Publication Date
Mar 28, 1994
Accession Number
ADD016316

Entities

People

  • Gregory Nau
  • Irwin Schneider
  • Ishwar Aggarwal
  • Kenneth H. Ewing
  • Thomas Bilodeau

Organizations

  • United States Department of the Navy

Tags

Communities of Interest

  • Sensors

DTIC Thesaurus Topics

  • Angle Of Incidence
  • Chlorinated Hydrocarbons
  • Detectors
  • Environment
  • Fibers
  • Hydrocarbons
  • Light Sources
  • Liquids
  • Materials
  • Optical Fibers
  • Photodetectors
  • Refractive Index

Fields of Study

  • Physics

Readers

  • Aquatic Ecology
  • Optical Fiber Sensing and Electromagnetic Propagation.
  • Spectroscopy.