Design of a High Resolution Spatial Heterodyne Interferometer

摘要

Several new spatial heterodyne interferometers were evaluated using ray tracinganalysis. A spherical grating interferometer was examined and found to have nonlinear fringe patterns that are difficult to interpret. A new plane grating interferometer was designed, built and tested using a visible light laser as the source. The new design uses two mirrors and a single, planar diffraction grating to divide and recombine incident collimated light. The zero and first order ray paths recombine to produce a high contrast, linear, interference fringe pattern suitable for Fourier Transform analysis. The instrument has the potential to perform extremely high resolution spectroscopy in the FUV and EUV portions of the electromagnetic spectrum with resolving powers on the order of 10 6. High resolution analysis of emission line profiles should enable an observer to more accurately determine atmospheric temperature and density profiles. The simple, lightweight and compact instrument has no moving parts and is suitable for remote sensing from sounding rocket or satellite platforms.