Integrated optics in an electrically scanned imaging Fourier transform spectrometer

Breckinridge, James B.; Ocallaghan, Fred G.

An efficient, lightweight and stable, Fourier transform spectrometer was developed. The mechanical slide mechanism needed to create a path difference was eliminated by the use of retro-reflecting mirrors in a monolithic interferometer assembly in which the mirrors are not at 90 degrees to the propagation vector of the radiation, but rather at a small angle. The resulting plane wave fronts create a double-sided inteferogram of the source irradiance distribution which is detected by a charge-coupled device image sensor array. The position of each CCD pixel in the array is an indication of the path difference between the two retro-reflecting mirrors in the monolithic optical structure. The Fourier transform of the signals generated by the image sensor provide the spectral irradiance distribution of the source. For imaging, the interferometer assembly scans the source of irradiation by moving the entire instrument, such as would occur if it was fixedly mounted to a moving platform, i.e., a spacecraft. During scanning, the entrace slot to the monolithic optical structure sends different pixels to corresponding interferograms detected by adjacent columns of pixels of the image sensor.

Document ID

19940005143

Acquisition Source

Legacy CDMS

Document Type

Other - Patent

Authors

Date Acquired

August 16, 2013

Publication Date

July 10, 1982

Subject Category

Accession Number

94N71898

Funding Number(s)

Distribution Limits

Public

Work of the US Gov. Public Use Permitted.

Patent

US-PATENT-4,523,846|NASA-CASE-NPO-15844-1

Patent Application

US-PATENT-APPL-SN-416443

Available Downloads

Name

Type

19940005143.pdf

STI

No Preview Available

NTRS

NTRS - NASA Technical Reports Server

Available Downloads

Related Records