Volume phase holographic grating based digital holographic interferometer for measurement of temperature distribution and temperature fluctuations in diffusion flames

Abstract

Optical measurement techniques are of immense importance for research in engineering, industrial production and biomedical applications. In this paper, an experimental study to measure temperature, temperature distribution, and temperature fluctuations in diffusion flames has been conducted using a volume phase holographic grating (VPHG) based digital holographic interferometric (DHI) system. VPHG made on Dichromated gelatin provides high diffraction efficiency and minimizes stray light and coherent speckle noise. The results obtained from VPHG based DHI system show a good agreement with temperature measured by thermocouple. The proposed system is compact, robust, requires lesser number of optical components, simple to align and easy to implementation.