Digital Recording and Numerical Reconstruction of Holograms: A New Optical Diagnostic for Combustion

Digital holographic interferometry (DHI) is a relatively newer imaging and measurement technique that electronically records a hologram (e.g., on a CCD) and reconstructs it using a numerical method. Cumbersome chemical processing of the hologram is avoided in DHI, thereby providing greater flexibility, speed, and the potential for real time processing. In conventional holography fringes that are neither bright nor dark on a hologram cannot be accurately resolved. The DHI technique reported so far has not yet been used for combustion applications. Herein, we will evaluate its efficacy for making temperature measurements in flames and assess its applicability through a simulation. The double exposures associated with the holographic technique are each considered recorded by a hypothetical CCD sensor at separate times. We have applied the principles of Fourier optics to develop a numerical method for hologram reconstruction.Copyright © 2002 by ASME