D. Naylor*, B. Gom, A. Huber, A. Anderson, A. Christiansen, W. Jellema, B. Lap, I. Veenendaal, A. Cournoyer, F. Grandmont, T. Fulton, S. Gunuganti, and P. Ade. “Development of a cryogenic far-infrared post-dispersed polarizing Fourier transform spectrometer”. In: OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES), pp. FM5C.3, 2021. Washington, DC, USA. DOI: 10.1364/FTS.2021.FM5C.3. Presentation
Questions about this publication? Contact me.
The sensitivity of state-of-the-art detectors is such that in future far-infrared space astronomy missions the multiplex disadvantage of Fourier transform spectrometers becomes prohibitive unless the spectral bandpass can be restricted to the order of a few tenths of one percent. The most widely considered method is to use a diffraction grating as the post-dispersing component. To achieve the required high dispersion, equivalent to a resolving power of R ~ 300, over a broad spectral range (Δλ/λ ~ 0.5) the diffraction grating must operate at high angles of incidence where it exhibits a strong polarization dependence, having high and uniform efficiency (~80%) to TM polarized light, but lower and variable efficiency (10–40%) to TE polarized light. A Martin-Puplett polarizing interferometer is able to exploit this dependency by using the polarizing encoding properties of the interferometer to optimally couple to the TM grating modes. To explore the challenges of this hybrid spectrometer, we are developing a cryogenic, far-infrared post-dispersed polarizing FTS (PDPFTS).