Project Title:

A Holographic Interferometer Spectrometer for Hypersonic Flow

02.04-0688A
NAS2-13171
A Holographic Interferometer Spectrometer for
	Hypersonic Flow
Metrolaser
	18006 Skypark Circle #108
	Irvine, CA 92714-6428
		James D. Trolinger
(714-553-0688)

Abstract:

	Holographic interferometry, widely used for diagnosis of flow fields, provides an
instantaneous, three-dimensional density distribution by observation of the fringe
variations of an interferogram. When optical path-length changes exceed one wavelength
of light, the flow field can be easily observed. When optical path-length changes
are much less than a wavelength of light, the problem is complicated since fringe
shifts are barely visible. A problem of current critical interest in aerodynamics
is the diagnosis of hypersonic flows involving low densities, short path-lengths,
and the mixing of flows. As a result, improved sensitivity and the ability to distinguish
constituents are needed. This project combines unique and innovative concepts with
state-of-the-art hardware to improve sensitivity and information content by orders
of magnitude over current systems. Specifically, the innovations include recording
the Fourier transform at resonance with tunable or multiple wavelength lasers and
reconstructing with a new phase shifting technique.

Potential Commercial Application:

Potential Commercial Applications: This system will have applications in industries
requiring flow diagnoses in hypersonic wind tunnels, combustion facilities, and other
types of test facilities.