A Vacuum Waveguide Filter Bank Spectrometer for Far-Infrared Astrophysics.

Traditional technologies for far-infrared (FIR) spectroscopy generally involve bulky dispersive optics. Integrated filter bank spectrometers promise more compact designs, but implementations using superconducting transmission line networks become lossy at terahertz frequencies. We describe a novel on-chip spectrometer architecture designed to extend this range.

SLAC microresonator RF (SMuRF) electronics: A tone-tracking readout system for superconducting microwave resonator arrays.

We describe the newest generation of the SLAC Microresonator RF (SMuRF) electronics, a warm digital control and readout system for microwave-frequency resonator-based cryogenic detector and multiplexer systems, such as microwave superconducting quantum interference device multiplexers (μmux) or microwave kinetic inductance detectors. Ultra-sensitive measurements in particle physics and astronomy increasingly rely on large arrays of cryogenic sensors, which in turn necessitate highly multiplexed readout and accompanying room-temperature electronics. Microwave-frequency resonators are a popular tool for cryogenic multiplexing, with the potential to multiplex thousands of detector channels on one readout line.

1.6:1 bandwidth two-layer antireflection structure for silicon matched to the 190-310 GHz atmospheric window.

Although high-resistivity, low-loss silicon is an excellent material for terahertz transmission optics, its high refractive index necessitates an antireflection treatment. We fabricated a wide-bandwidth, two-layer antireflection treatment by cutting subwavelength structures into the silicon surface using multi-depth deep reactive-ion etching (DRIE). A wafer with this treatment on both sides has <-20  dB (<1%) reflectance over 187-317 GHz at a 15° angle of incidence in TE polarization.