Spectral Effects in an Interferometer for Off-Axis Sources

abstract: Fourier Transform Infrared (FTIR) Spectrometers are used to determine surface composition of celestial bodies such as asteroids or planets by collection of infrared spectral data. However, degraded performance for shorter wavelengths may exist when the target does not fill the field of view and may be off-axis. Further study of the optical implications of such use cases would inform future design. This research project aims to develop a systematic method of rapid prototyping in order to progressively simulate optical conditions to characterize the off-axis implications in FTIR spectrometers regarding effects on spectral data measured. With such findings, FTIR spectrometers may be developed to effectively accommodate a larger field of view beyond the current state-of-the-art without increasing the corresponding package size of aft optics such as interferometer assemblies. Throughput may be further increased than current limitations or smaller aft optics systems may be designed with the same throughput. Specific use cases which would otherwise result in degradation of spectral data could potentially be accommodated, all effectively increasing capability of the current technology. With this intent, a preliminary test setup has been developed and initial results were collected