"Collaborative Research: Demonstration of Superspec: a Superconducting On-Chip Spectrometer for mm and submm Wavelength Astrophysics"

Project: Research project


Overview: Page A This proposal aims to develop a novel ultra-compact spectrometer-on-a-chip for sub-millimeter and millimeter (submm/mm) wavelength astronomy. It uses planar lithographed super-conducting transmission-line filters to sort incident radiation by frequency to an array of direct detectors. The first part of the program involves iterated design and testing to achieve three goals: (1) reduce the NEP of existing prototype devices by factor of 2-4 to reach the photon noise limit, (2) demonstrate accurate channel spacing and adequate dielectric losses in a dense filter bank, (3) extend the prototype 1 mm architecture to shorter wavelengths. Once these goals have been met, a demonstration instrument will be built and integrated. This instrument will consist of two single-pixel SuperSpec prototypes, one at 1-mm wavelength and a second covering the 850 and 650 micron atmospheric windows. Each will have resolving power 600 with 540 Kinetic Inductance Detectors. This instrument will then be deployed for a brief observing run at a ground based 10m-class submm telescope, either the Caltech Submillimeter Observatory (CSO) or the Submillimeter Telescope (SMT). This field demonstration will consist of pointed observations of spectral lines in high-redshift dusty star forming galaxies. Intellectual Merit : The SuperSpec spectrometer is naturally wideband and can be very low loss, enabling background-limited spectroscopy from mountaintop, balloon, and even space platforms. While existing di raction-grating spectrometers off ering similar capabilities are bulky assemblies of order of a meter in size, SuperSpec can fit on a few square cm chip. The approach builds on a decade of success in planar superconducting circuits and KID detectors, and will eventually enable Integral Field Units consisting of 2-D arrays of spectrometers. A successful SuperSpec demonstration will immediately enable two new astrophysical experiments which can not be pursued with existing technology: 1. Rapid follow-up submm/mm survey spectroscopy of distant dusty galaxies with a multi-object spectrometer (MOS) on a large single-dish telescope such as CCAT. A 100-object wideband MOS on CCAT will be much faster than ALMA for redshift-blind follow-up of galaxies discovered in the current and planned far-IR/submm/mm imaging surveys. This instrument will obtain redshifts and basic interstellar medium properties at a rate of hundreds of galaxies per night, yielding tens of thousands over a few-year campaign with CCAT and provide the first large-scale unbiased millimeter-wave redshift survey to identifying particularly interesting (e.g. high-redshift) objects for detailed study via tuned observations with ALMA. 2. Tomographic studies of the epoch of reionization (EoR) via intensity mapping of the red-shifted 158 micron [CII] fi ne-structure transition. While the individual galaxies that reionized the Universe are difficult to detect with even JWST and ALMA, their aggregate properties can be measured statistically. With suitable 2-D spectrometer formats (100 pixels), the [CII] emission from faint EoR galaxies is detectable through its fluctuations in a spatial / spectral data cube. Broader Impacts : KID technology will be substantially advanced in two ways: 1) Sensitivity will be improved two orders of magnitude beyond that demonstrated to date on-sky, enabling new experiments ranging from space and balloon-borne systems as well as optical/near-IR instruments. 2) Development of a low-cost, FPGA-based KID readout designed to operate at VHF frequencies will enable future large-format KID systems. The program includes a training component that will provide hands-on instrumentation experience for an undergraduate student (at Caltech) and the basis of dissertation research for three Ph.D. students (at the U. Chicago, U. Colorado, and Arizona State). Finally, two postdoctoral scholars at Caltech will gain unique career-advancing experience at the forefront of superconducting detector development and instrument deployment.
Effective start/end date8/15/147/31/17


  • National Science Foundation (NSF): $255,190.00


time measurement
space platforms
atmospheric windows
James Webb Space Telescope
parabolic reflectors
incident radiation