A design study on terahertz interferometry in Antarctica

Terahertz interferometry from high altitude site in Antarctica is proposed. Requirements for future terahertz astronomy are followed by comparison of interferometer technologies. Heterodyne interferometer can use matured technology and achieve high frequency resolution, whereas, direct detector interferometer can achieve observations in large bandwidth and wide field of view using focal plane arrays. As an example of direct detector interferometry multi-Fourier transform interferometer (MuFT) is introduced, which utilize Martin-Puplett type Fourier transform spectrometer, which is essential to realize multiplying interferometry to avoid atmospheric background fluctuation. As another example, photon counting interferometry is introduced. By implementing fast response FIR detectors to measure photon arrival time, visibility can be measured by the correlation of the photon statistics.