SuperSpec, The On-Chip Spectrometer: Improved NEP and Antenna Performance

• Published in: Journal of low temperature physics Vol. 193; no. 3-4; pp. 408 - 414
• Main Authors: Wheeler, Jordan, Hailey-Dunsheath, S., Shirokoff, E., Barry, P. S., Bradford, C. M., Chapman, S., Che, G., Doyle, S., Glenn, J., Gordon, S., Hollister, M., Kovács, A., LeDuc, H. G., Mauskopf, P., McGeehan, R., McKenney, C., Reck, T., Redford, J., Ross, C., Shiu, C., Tucker, C., Turner, J., Walker, S., Zmuidzinas, J.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2018; Springer Nature B.V
• Subjects: Antennas; Bandwidths; Broadband; Characterization and Evaluation of Materials; Condensed Matter Physics; Galaxies; Low temperature physics; Magnetic Materials; Magnetism; New technology; Physics; Physics and Astronomy; Red shift; Slot antennas; Spectrometers; Spectrum analysis; NEP; Bow tie; Kinetic inductance detectors; Spectrometer; Antenna; mm-wave
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1007/s10909-018-1926-z

SuperSpec is a new technology for mm and sub-mm spectroscopy. It is an on-chip spectrometer being developed for multi-object, moderate-resolution ( R ∼ 300 ), large bandwidth survey spectroscopy of high-redshift galaxies for the 1 mm atmospheric window. This band accesses the CO ladder in the redshift range of z =  0–4 and the [CII] 158  μ m line from redshift z =   5–9. SuperSpec employs a novel architecture in which detectors are coupled to a series of resonant filters along a single microwave feedline instead of using dispersive optics. This construction allows for the creation of a full spectrometer occupying only ∼ 10 cm 2 of silicon, a reduction in size of several orders of magnitude when compared to standard grating spectrometers. This small profile enables the production of future multi-beam spectroscopic instruments envisioned for the millimeter band to measure the redshifts of dusty galaxies efficiently. The SuperSpec collaboration is currently pushing toward the deployment of a SuperSpec demonstration instrument in fall of 2018. The progress with the latest SuperSpec prototype devices is presented; reporting increased responsivity via a reduced inductor volume (2.6  μ m 3 ) and the incorporation of a new broadband antenna. A detector NEP of 3–4  × 10 - 18  W/Hz 0.5 is obtained, sufficient for background-limited observation on mountaintop sites. In addition, beam maps and efficiency measurements of a new wide-band dual bow-tie slot antenna are shown.