Photonic Integrated Circuit TUned for Reconnaissance and Exploration (PICTURE)

Goals and Objectives: Future planetary science missions require smaller, lighter and lower power instrumentation, while delivering comparable or higher performance than previous generations. The near-infrared (1-5 um) emission of planets, moons, comets and asteroids is rich in information, including gas composition and surface mineralogy. We propose to develop a next-generation near-infrared spectrometer for future planetary missions, based on integrated photonics technology. In this PICASSO, we will build a fully-operational instrument prototype focused on the CO spectral band at 4.6-4.8 um, which is of key importance to cometary science. Successor instruments can be modified straightforwardly for spectroscopy of the nearby bands of CO2, H2O, CH4 for wide applicability in planetary science, by changing the reference laser. This technology development and demonstration will provide an important proof of concept for future flight instruments. Methodology: We will design, build and test a compact, high efficiency coherent (heterodyne) optical spectrometer with associated electronics to combine and leverage recent technological breakthroughs by the proposing team and others. Our spectrometer takes advantage of three significant advances in the field of photonics in recent years – (a) photonic lantern (PL) technology for astronomy; (b) arrayed waveguide gratings (AWGs); and (c) photonics integrated circuits (PIC) for the telecommunication industry. The PIC allows the complex integration of electro-optics components, including AWGs and local oscillators for heterodyne detection, in a compact form factor that will provide smaller, lighter, and lower-power instrumentation. We will leverage the significant earlier progress by our team members at NRL and UCSB toward high-performance near-infrared (NIR) laser arrays integrated on a silicon (Si) chip. During the 3-year performance period we will (i) develop key components and subsystems; (ii) integrate sub-systems to build a complete instrument; (iii) demonstrate and validate high sensitivity measurements in conjunction with our existing infrastructure and instrumentation. The entrance TRL for this instrument is 2, which will be raised to 4 on completion. Relevance: Our objective of developing a next-generation near-infrared spectrometer is highly relevant to the PICASSO goal of "the development of spacecraft-based instrument components and systems that show promise for use in future planetary missions". After proof of concept under PICASSO, a fully-ready flight instrument could be developed under MatISSE. A PICTURE-like instrument on a cometary mission will be capable of measuring the relative abundances of cometary volatiles, yielding important information on the primitive building blocks of the solar system. Cometary science has been highlighted in the recent Decadal Survey for Planetary Science (Chapter 4, Primitive Bodies) as being of high importance to NASA's strategic scientific goals. More broadly, the scientific capability of the proposed instrument can achieve multiple goals of solar system science, including the measurements of water and trace gases in the atmospheres of Mars, giant planets, and Titan, as well as the spectroscopy of asteroid and moon surface materials.