Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) is a versatile technique used for identifying the composition of geological materials and quantifying element abundances. The PLASMA (Pulsed Laser Ablation Sampling and Mass Analysis) investigation, supported through the NASA DALI (Development and Advancement of Lunar Instrumentation) program, is focused on the technical development of an LA-ICPMS instrument comprising a multiwavelength pulsed laser, low power plasma source, collision cell designed to separate Rb and Sr for radiometric dating, and heritage quadrupole mass spectrometer based on the analyzer flown on the Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover. Multi-wavelength laser pulses at 1064 nm, 532 nm, 266 nm, and 213 nm enable the analysis of water-bearing phases, support Raman spectroscopy, enhance the desorption of aromatic hydrocarbons, and promote the ablation of refractory geological phases, respectively. We report on the PLASMA’s solid-state, multiwavelength pulsed laser technology development. The fundamental 1064 nm laser, based on heritage spaceborne laser transmitter design, generates 4mJ, 5ns pulses at 10 Hz from ceramic Nd:YAG slab oscillator pumped by 885nm laser diode array. The ceramic Nd:YAG is highly doped with approximately 4 at% Nd, and with the use of an 885 nm in-band pumping, allows to operate at approximately twice the nominal performance of a 1% crystalline Nd:YAG pumped with 808 nm diode. Second, fourth and fifth harmonic generation of the fundamental laser is achieved using LBO and BBO crystals with optimizing the output energies of 532 nm, 266 nm, and 213 nm to reach the energy fluences up to 5 J/cm2. The wavelength of laser output is selectable on-demand.
The Goddard Laser for Absolute Measurement of Radiance (GLAMR) is a mobile spectral and radiometric sensor characterization facility based at NASA/Goddard Space Flight Center. Based on NIST’s traveling Spectral Irradiance and Radiance Calibration using Uniform Sources (SIRCUS), GLAMR consists of a system of tunable lasers to generate quasi-monochromatic energy between 310 and 2500nm, a large integrating sphere to provide a full aperture uniform source, a control system to automate operations and a data system to record and serve telemetry. GLAMR was used to characterize the Ocean Color Instrument (OCI) to be launched aboard the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission. The test of the OCI flight instrument took place in October 2022. GLAMR will be used to characterize the CLARREO Pathfinder (CPF) instrument in September 2023. Both programs had stringent calibration requirements on GLAMR, necessitating additional characterization of GLAMR radiometric uncertainty and improvements in the NIST traceability. This paper will discuss the improvement in the GLAMR uncertainty budget and the performance of GLAMR for the OCI instrument as well as the upcoming test for CPF.
The Landsat-9 satellite will carry the Operational Land Imager-2 (OLI-2) as one of its payloads. This instrument is a clone of the Landsat-8 OLI and its mission is to continue the operational land imaging of the Landsat program. The OLI-2 will continue to populate an archive of Landsat earth images that dates back to 1972. The OLI-2 instrument is not significantly different from OLI though the instrument-level pre-launch spectral characterization process was much improved. While OLI was characterized by a double monochromator system, the OLI2 spectral characterization made use of the Goddard Laser for Absolute Measurement of Radiance (GLAMR), a system of tunable lasers that cover 350-2500nm which are fiber-coupled to a 30-in integrating sphere and is monitored by NISTtraceable radiometers. GLAMR allowed the spectral characterization of every detector of the OLI-2 focal plane in nominal imaging conditions. The in-band relative spectral responses were sampled at 1 or 2nm wavelength increments and the out-of-band responses at 10 or 20nm wavelength increments (increment is dependent on spectral band/region). The final relative spectral responses (RSRs) represent the best characterization any Landsat instrument spectral response. This paper will cover the results of the instrument-level spectral characterization, including in-band response, out-of-band response, spectral cross-talk and spectral uniformity.
The terahertz (THz) region of the electromagnetic spectrum, broadly defined as between 300 GHz and 30 THz, is of growing importance in fields as diverse as communications, medicine, astronomy, security, biology and materials science. Despite this, the technologies for detection of THz radiation are still comparatively immature. The most sensitive THz detectors are typically slow and require cryogenic cooling, and conversely the fastest detectors lack the sensitivity to measure weak signals. We describe here recent work to employ new two-dimensional (2D) materials for the detection of THz waves.
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.