Realization of multiplying type interferometer with 2-elements 0.3K bolometer detectores

We have developed two-elements 0.3K high sensitive bolometer detectors system optimized to Multi- Fourier Transform interferometer (MuFT) to realize the multiplying type bolometric astronomical interferometer in millimeter and submillimeter wave bands. A wiregrid polarizer is set in the detector system. The signal led to the bolometer detectors system is then divided into two parts. One of the two bolometer elements receives the reflected signal while the other receives the transmitted signal. Since phases of mutual coherence functions in two signals are shifted 71 ,the difference of reflected and transmitted signals reproduces full mutual coherence function and can easily remove the baseline fluctuations. This method is for the first time succeeded in moon observation at Nobeyama Radio Observatory, Japan, 2007.