Phase Gratings as Lo-distributors in Submm Heterodyne Arrays

Phase gratings have found an important application in the submm wavelength range with the development of heterodyne arrays in the past few years. These devices can be used as efficient beam splitters to match the signal beam of a single local oscillator source to an array of detector devices such as SISmixers or HEBs. Here we report on a phase grating developed for CHAMP theCarbon-Heterodyne-Array ofMPIfR which is currently operating at the Caltech Submillimeter Telescope on Mauna Kea [1]. For further applications, such as heterodyne arrays for higher frequencies, we continued our work on designing phase gratings to enhance their efficiencies and to provide solutions for future array projects. Here we report on an algorithm we have developed as a design tool for phase gratings providing solutions for any desired array, nearly independent on the desired beam configuration.