More Like this

1. Simulation and calibration of a compact millimeter-wavelength Fourier transform spectrometer

   https://doi.org/10.1364/AO.397312  

   Liu, Mira ; Pan, Zhaodi ; Basu Thakur, Ritoban ; Meyer, Stephan S. ( September 2020 , Applied Optics)

   This paper presents the simulation and calibration of a Fourier transform spectrometer (FTS) developed to measure the spectrum of radiation sources between 50 GHz and 330 GHz, such as the cosmic microwave background. The recorded signal is modified from the ideal by properties of the interferometer and the detection system. We have developed a ray-trace-based simulation with which we can model these effects. The model can be verified with measurements and used to understand the instrument’s systematic effects and to design new optimized configurations. The optimization comprises parameters of the design, such as large étendu, maximal spectral resolution, compact size, operational simplicity, and light weight, that conflict and need to be balanced. The numerical simulation consists of two parts: time-stream signal analysis and a ray-trace-based simulation that includes polarization and path length calculations and can account for the effects of beam loss and change of focus as the delay-generating mirror travels on its path. The simulation can study the coherence level and frequency resolution of the FTS instrument. While not exercised in this study, the simulation also can be used to study the effect of mirror figure and polarizer non-idealities, walk-off rays in the beam due to the large étendu, as wellmore »as misalignment of optical elements. We then present the comparison between simulations of a spectrally unresolved source and measurements by the FTS.

   « less
2. The Exoplanet Transmission Spectroscopy Imager (ETSI)

   https://doi.org/10.1117/12.2562371  

   Limbach, Mary Anne ; Schmidt, Luke M. ; DePoy, Darren L. ; Mason, Jeffrey C. ; Scobey, Mike ; Brown, Pat ; Taylor, Chelsea ; Marshall, Jennifer L. ( December 2020 , Proc. SPIE 11447, Ground-based and Airborne Instrumentation for Astronomy VIII)

   Evans, Christopher J. ; Bryant, Julia J. ; Motohara, Kentaro (Ed.)

   We present the design of a novel instrument tuned to detect transiting exoplanet atmospheres. The instrument, which we call the exoplanet transmission spectroscopy imager (ETSI), makes use of a new technique called common-path multi-band imaging (CMI). ETSI uses a prism and multi-band lter to simultaneously image 15 spectral bandpasses on two detectors from 430 􀀀 975nm (with a average spectral resolution of R = =
    = 23) during exoplanet transits of a bright star. A prototype of the instrument achieved photon-noise limited results which were below the atmospheric amplitude scintillation noise limit. ETSI can detect the presence and composition of an exoplanet atmosphere in a relatively short time on a modest-size telescope. We show the optical design of the instrument. Further, we discuss design trades of the prism and multi-band lter which are driven by the science of the ETSI instrument. We describe the upcoming survey with ETSI that will measure dozens of exoplanet atmosphere spectra in  2 years on a two meter telescope. Finally, we will discuss how ETSI will be a powerful means for follow up on all gas giant exoplanets that transit bright stars, including a multitude of recently identi ed TESS (NASA's Transiting Exoplanet Surveymore »Satellite) exoplanets.« less
3. Panoramic optical and near-infrared SETI instrument: overall specifications and science program

   https://doi.org/10.1117/12.2314268  

   Wright, Shelley A. ; Horowitz, Paul ; Maire, Jérôme ; Chaim-Weismann, Samuel A. ; Cosens, Maren ; Drake, Frank D. ; Howard, Andrew W. ; Marcy, Geoffrey W. ; Siemion, Andrew P. ; Stone, Remington P. ; et al ( July 2018 , Proceedings Volume 10702, Ground-based and Airborne Instrumentation for Astronomy VII; 107025)

   We present overall specifications and science goals for a new optical and near-infrared (350 - 1650 nm) instru- ment designed to greatly enlarge the current Search for Extraterrestrial Intelligence (SETI) phase space. The Pulsed All-sky Near-infrared Optical SETI (PANOSETI) observatory will be a dedicated SETI facility that aims to increase sky area searched, wavelengths covered, number of stellar systems observed, and duration of time monitored. This observatory will offer an “all-observable-sky” optical and wide-field near-infrared pulsed tech- nosignature and astrophysical transient search that is capable of surveying the entire northern hemisphere. The final implemented experiment will search for transient pulsed signals occurring between nanosecond to second time scales. The optical component will cover a solid angle 2.5 million times larger than current SETI targeted searches, while also increasing dwell time per source by a factor of 10,000. The PANOSETI instrument will be the first near-infrared wide-field SETI program ever conducted. The rapid technological advance of fast-response optical and near-infrared detector arrays (i.e., Multi-Pixel Photon Counting; MPPC) make this program now feasible. The PANOSETI instrument design uses innovative domes that house 100 Fresnel lenses, which will search concurrently over 8,000 square degrees for transient signals (see Maire et al. and Cosensmore »et al., this conference). In this paper, we describe the overall instrumental specifications and science objectives for PANOSETI.« less
4. The wide-field infrared transient explorer (WINTER)

   https://doi.org/10.1117/12.2561210  

   Lourie, Nathan P. ; Baker, John W. ; Burruss, Richard S. ; Egan, Mark D. ; Furész, Gábor ; Frostig, Danielle ; Garcia-Zych, Allan A. ; Ganciu, Nicolae ; Haworth, Kari ; Hinrichsen, Erik ; et al ( December 2020 , X-Ray, Optical, and Infrared Detectors for Astronomy IX)

   Evans, Christopher J. ; Bryant, Julia J. ; Motohara, Kentaro (Ed.)

   The Wide-Field Infrared Transient Explorer (WINTER) is a new infrared time-domain survey instrument which will be deployed on a dedicated 1 meter robotic telescope at the Palomar Observatory. WINTER will perform a seeing-limited time domain survey of the infrared (IR) sky, with a particular emphasis on identifying r -process material in binary neutron star (BNS) merger remnants detected by LIGO. We describe the scientific goals and survey design of the WINTER instrument. With a dedicated trigger and the ability to map the full LIGO O4 positional error contour in the IR to a distance of 190 Mpc within four hours, WINTER will be a powerful kilonova discovery engine and tool for multi-messenger astrophysics investigations. In addition to follow-up observations of merging binaries, WINTER will facilitate a wide range of time-domain astronomical observations, all the while building up a deep coadded image of the static infrared sky suitable for survey science. WINTER's custom camera features six commercial large-format Indium Gallium Arsenide (InGaAs) sensors and a tiled optical system which covers a <1-square-degree field of view with 90% fill factor. The instrument observes in Y, J and a short-H (Hs) band tuned to the long-wave cutoff of the InGaAs sensors, covering amore »wavelength range from 0.9 - 1.7 microns. We present the design of the WINTER instrument and current progress towards final integration at the Palomar Observatory and commissioning planned for mid-2021.« less
5. Readout and cooling of the WINTER InGaAs camera

   https://doi.org/10.1117/12.2630602  

   Frostig, Danielle ; Burdge, Kevin ; De, Kishalay ; Fűrész, Gábor ; Haworth, Kari ; Hinrichsen, Erik ; Karambelkar, Viraj R. ; Kasliwal, Mansi M. ; Lourie, Nathan P. ; Malonis, Andrew C. ; et al ( August 2022 , SPIE Astronomical Telescopes and Instrumentation (2022))

   Holland, Andrew D. ; Beletic, James (Ed.)

   The Wide-Field Infrared Transient Explorer (WINTER) is a new time-domain instrument which will perform a seeing-limited survey of the near-infrared sky. Deployed on a dedicated 1-meter robotic telescope at Palomar Observatory, WINTER is designed to study transients of particular interest in the near-infrared including kilo-novae from gravitational-wave sources, supernovae, tidal disruption events, and transiting exoplanets around low mass stars with surveys to a depth of J=21 magnitudes. WINTER's custom camera combines six commercial large-format Indium Gallium Arsenide (InGaAs) sensors, observing in Y, J, and a short-H (Hs) band filters (0.9-1.7 microns), and employs a novel tiled optical design to cover a >1 degree squared field of view with 90% fill factor. Each wide-format (1920 x 1080 pixels) InGaAs sensor operates at T = -50°C with a thermoelectric cooler, achieving background-limited photometry without cryogenic cooling. The tiled InGaAs sensors result in a wide field-of-view instrument with significant cost savings when compared to HgCdTe sensors. We present WINTER's novel readout scheme, which includes custom electronics, firmware, and software for low-noise, real-time readout of the InGaAs sensors, including up to a 30x speed up of data reduction using GPUs. This work also outlines the cooling design for warm (T = -50°C) operation ofmore »the sensors with a two-stage thermometric cooler, copper heat pipes, and liquid cooling. We conclude with updates on the alignment, integration, and test of the WINTER instrument with a projected first light in Fall 2022.« less