This paper describes a cryogenic optical testbed developed to characterize µ-Spec spectrometers in a dedicated dilution refrigerator (DR) system. μ-Spec is a far-infrared integrated spectrometer that is an analog to a Rowland-type grating spectrometer. It employs a single-crystal silicon substrate with niobium microstrip lines and aluminum kinetic inductance detectors (KIDs). Current designs with a resolution of R = λ/Δλ = 512 are in fabrication for the EXCLAIM (Experiment for Cryogenic Large Aperture Intensity Mapping) balloon mission. The primary spectrometer performance and design parameters are efficiency, NEP, inter-channel isolation, spectral resolution, and frequency response for each channel. Here we present the development and design of an optical characterization facility and preliminary validation of that facility with earlier prototype R=64 devices. We have conducted and describe initial optical measurements of R = 64 devices using a swept photomixer line source. We also discuss the test plan for optical characterization of the EXCLAIM R = 512 μ-Spec devices in this new testbed.
HIRMES, SOFIA’s third generation science instrument, delivers spectroscopy at wavelengths between 25 and 122 um and resolving powers (RP) between 600 and 100,000. The detectors arrays are background-limited transition edge sensed bolometers. Here we focus on the development, testing, and performance of the series of 8 tunable cryogenic scanning Fabry-Perot interferometers (FPI) that deliver the imaging (RP = 2000), and the long-slit medium resolution (RP = 10,000) and high resolution (RP = 100,000) spectroscopic modes. The FPIs use free-standing metal meshes mirrors, flexible parallelogram translations stages, PZTs and/or cryomoters for displacement. and capacitive sensors for displacement measure.
We will present a status update on the development of HIRMES, the third generation instrument for SOFIA (Stratospheric Observatory for Infrared Astronomy).
HIRMES (HIgh Resolution Mid-infrarEd Spectrometer) will cover the wavelength range between 25 micron and 122 micron with a spectral resolution of up to R~100,000. It will use two arrays of Transition Edge Sensed (TES) bolometers. One of the arrays consists of 8 16-pixel strips, for the high-resolution mode, where the pixel area and backshorts are optimized for 8 different wavelength regimes. The second detector consists of a 16x64 array with excellent sensitivity over the full wavelength range, and it will be used for the mid-resolution (R~19,000) and low-resolution (R~2,000 and R~600) observing modes. Both detector arrays will have background limited performance with NEPs of < 2E-17 W/Hz^(1/2) for the low-resolution array and < 3E-18 W/Hz^(1/2) for the high-resolution array.
HIRMES will employ several Fabry-Perot Interferometers (FPI) for the low- (R~2000), mid- (R~19,000), and high-resolution (R~100,000) observing modes. In addition, three gratings with resolutions of R~600 will be used to order-sort FPI transmission peaks, and also to obtain low resolution broad bandwidth spectra.
HIRMES's main science goals are to study the evolution of protoplanetary disks as well as to investigate the origin of Hydrogen and Deuterium in the Solar System.
The high spectral resolution observations of the HD 1-0 R(0) line at 112 micron will determine the gas mass and kinematics in protoplanetary disks, while the observations of the [OI] 63 micron and H2O lines reveal the amount of Oxygen and H20 within the snowline. Low spectral resolution observations of solid-state H20 ice features at ~43 and ~63 micron will determine the amount of water ice beyond the snowline. Measurements of the molecular hydrogen line and numerous HD lines at mid-resolution will help to estimate the H/D ratio in the Solar System. In addition, the low-resolution FPI is well suited to map fine-structure line emission from nearby galaxies.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.