Design and performance of a dual polarizing detector system for broadband astronomical spectroscopy at submillimeter wavelengths

The design and performance of a dual polarizing bolometer detector system for use with a polarizing Fourier transform spectrometer to conduct broadband astronomical spectroscopy at submillimeter wavelengths is presented. The system features a fully differential electronics design which virtually eliminates common mode noise. The optical design efficiently rejects unwanted radiation, both spectrally and spatially, while minimizing the effects of resonant optical cavities. The system is cooled by an efficient, closed cycle He4–3He refrigerator which is cycled under computer control. The noise performance of the system is determined from analysis of electrical, optical, and spectral measurements, and the results are compared with a theoretical bolometer model.