Optimization of an Optical Testbed for Characterization of EXCLAIM u-Spec Integrated Spectrometers

• Published in: arXiv.org
• Main Authors: Rahmani, Maryam, Barrentine, Emily M, Switzer, Eric R, Barlis, Alyssa, Brown, Ari D, Cataldo, Giuseppe, Connors, Jake A, Ehsan, Negar, Essinger-Hileman, Thomas M, Grant, Henry, Hays-Wehle, James, Wen-Ting Hsieh, Mikula, Vilem, S Harvey Moseley, Noroozian, Omid, Quijada, Manuel A, Patel, Jessica, Stevenson, Thomas R, Tucker, Carole, U-Yen, Kongpop, Volpert, Carolyn G, Wollack, Edward J
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 12.12.2023
• Subjects: Etalons; Far infrared radiation; Galaxies; Gratings (spectra); Inductance; Physics - Instrumentation and Methods for Astrophysics; Red shift; Silicon; Spectral sensitivity; Spectrometers; Test stands
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2312.07656

We describe a testbed to characterize the optical response of compact superconducting on-chip spectrometers in development for the Experiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) mission. EXCLAIM is a balloonborne far-infrared experiment to probe the CO and CII emission lines in galaxies from redshift 3.5 to the present. The spectrometer, called u-Spec, comprises a diffraction grating on a silicon chip coupled to kinetic inductance detectors (KIDs) read out via a single microwave feedline. We use a prototype spectrometer for EXCLAIM to demonstrate our ability to characterize the spectrometers spectral response using a photomixer source. We utilize an on-chip reference detector to normalize relative to spectral structure from the off-chip optics and a silicon etalon to calibrate the absolute frequency.