Interferometer

Abstract

An interferometer (10) is provided that has a stage (28) configured to have a linear motion path. A first retroreflector (18) and a second retroreflector (24) are fixedly coupled to the stage (28). A tube (32) is provided, and the stage (28) is configured to reciprocate about the tube (32). A beamsplitter (14) and a 45° mirror (16) are disposed in the tube (32). A detector (22) is configured to detect light passing through the beamsplitter (14), and the beamsplitter (14) is configured to split an incident light beam into a transmitted beam (15) and a reflected beam (17), wherein the transmitted beam (15) passes to the second retroreflector (24) and the reflected beam (17) passes to the first retroreflector (18). The transmitted beam (15) and a reflected beam (17) are focused on the detector (22).

Description

FIELD OF THE INVENTION[0001]The embodiments described below relate to Fourier Transform Interferometers, and more particularly, to a Fourier Transform Interferometer having an improved mirror and beamsplitter arrangement.BACKGROUND[0002]The Michaelson Interferometer was invented in the late 1800's, and since has been widely adopted across many disciplines to create spectra from an incoming light source. Fourier Transform Interferometer based systems are used in research for assay determination, for chemical composition of samples such as for the pharmaceutical industry, on factory floors for monitoring effluent and / or air quality, etc. One application where interferometers have found particular success is in use related to detection of the infrared region of the electromagnetic spectrum. In such a role, Fourier Transform Interferometer Infra-Red (FTIR) systems may, for example, be used to measure trace gases in the earth's atmosphere.[0003]Atmospheric measurement systems are however...

AI Technical Summary

Benefits of technology

This configuration maintains interferometer accuracy by eliminating optical path limitations and self-correcting misalignment, enabling reliable operation in vibrating environments and allowing for arbitrarily large optical path differences, thus enhancing the interferometer's performance in aircraft applications.

Problems solved by technology

Atmospheric measurement systems are however often employed on aircraft, and thus exposed to high levels of vibration.

A fundamental design difficulty for maintaining interferometer accuracy stems from the need to maintain optical alignment of two opposing mirrors as they are physically moved when increasing the optical path difference (OPD) between them.

To ensure that an interferometer remains reliable, it must be substantially immune to environmental vibrations, but this is an extremely difficult task in aircraft applications.

Furthermore, optical misalignment introduced by a relative tilt between the base and translation mirror mount is largely self-correcting.

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