"We propose to develop a novel ultra-compact spectrograph-on-a-chip for the submillimeter and millimeter waveband. SuperSpec uses planar lithographed superconducting transmission-line filters to sort incident radiation by frequency to an array of direct detectors such as MKIDs. The system is naturally wideband and can be very low loss, enabling background-limited spectroscopy on the ground and in space, as is currently done with a diffraction grating spectrographs. But while moderate-resolution grating systems for the mm and submm bands have sizes measured in tens of centimeters, SuperSpec can have a size measured in millimeters. If successful, SuperSpec will pave the way for a new kind of astronomical instrument for the submm/mm: a 2-D array of hundreds to thousands of individual spectrometers, each simultaneously measuring a separate spectrum. With the possible exception of polarization, such an instrument extracts all available information from the light at a telescope focal plane.
SuperSpec thus offers the potential to revolutionize astrophysics in the far-IR through millimeter, an important spectral regime for which the the Astro2010 Decadal Survey made two specific recommendations for this decade: 1) Participate in the Japanese-led SPICA space telescope with a spectrometer instrument such as BLISS, and 2) Construct CCAT and its associated instrumentation. Depending on SPICA's schedule, SuperSpec technology could be injected and would enhance and extend the long-wavelength capability of BLISS or a similar instrument. Whether or not SPICA moves ahead quickly, our demonstration will position SuperSpec to be used in on CCAT and suborbital platforms this decade, paving the way for optimal science return with future NASA-led cryogenic far-IR space missions on the drawing board for the next decade: CALISTO/SAFIR and SPIRIT.
SuperSpec is based on propagation on a superconducting transmission line (TL). As radiation propagates along the line, it encounters a seri