µ-Spec: An Integrated Spectrometer for Terahertz Space Spectroscopy

Under APRA funding, we have developed a fully integrated R~64 submillimeter spectrometer. Using only single crystal Si and superconductors, our fabrication process is designed with the goal of minimizing loss in the spectrometer. High performance designs have been developed for all the required elements of the spectrometer. For example the slot antenna, power divider microstip delay lines, absorbers, and M icrowave Kinetic Inductance detectors (MKIDs) have been designed and buit, and the performance of a system operating at R~ 64 has been demonstrated. We l propose to develop and test a spectrometer with R~300. This device can be produced to sufficient accuracy with known fabrication tolerances. After the successful demonstration of the R~300 instrument, the devices will be ready for application in balloon or airborne applications.We will measure loss in the transmission lines to establish the limits of resolving power in such a materials system and will develop a phase adjuster to allow a diffraction limited delay network at the full resolution allowed by loss in the materials. We will demonstrate the performance of this system with R~1000 by the end of the proposed program. Arrays of such integrated spectrometers are ideal building blocks for a high redshift survey instrument, and its compact size may allow significant science to be done on Explorer Class Missions.