Feasibility of a Small Scale Intensity Correlation Interferometer

Abstract

Demand for high-resolution imaging capabilities for both space-based and ground-based imaging systems has created significant interest in improving the design of multi-aperture interferometry imaging systems. Interferometers are a desirable alternative to single aperture imaging systems due to the fact that the angular resolution of a single aperture system is dependent on the diameter of the aperture and the resolution of the image recording device (CCD or otherwise) which quickly results in increased size, weight, and cost. Interferometers can achieve higher angular resolutions with lower resolution recording mediums and smaller apertures by increasing the distance between the apertures. While these systems grow in both size, mechanical, and computational complexity, methods of testing large scale designs with small scale demonstration systems currently do not exist. This paper documents the performance of a small scale multi-aperture intensity correlation interferometer which is used to view a double slit image.

The interferometer consists of 2 avalanche photo-diodes connected to a data acquisition computer. The image is produced by shining light through the double slit image an image containment system. The sensors are placed at the far end of the image containment system, and their voltages are recorded and digitally filtered. This study presents the formulation of the design parameters for the interferometer, the assembly and design of the interferometer, and then analyzes the results of the imaging experiment and the methods used to attempt to prevent unwanted noise from corrupting the expected interference pattern. Codes in C and C++ are used to collect and analyze the data, respectively, while Matlab® was used to produce plots of binary data. The results of the analysis are then used to show that a small scale intensity correlation interferometer is indeed feasible and has promising performance.