Compact High-Power Widely Tunable Mid-IR Light Source for Planetary Exploration

Los Gatos Research, Inc. (LGR) and Professor Martin Fejer and his group at Stanford University propose to develop and demonstrate a compact, monolithic, efficient, high-power, narrow-linewidth tunable laser source operating in the 3.2-3.4 um wavelength region. LGR's mid-infrared (mid-IR) light source, based on a fiber-laser pumped monolithic optical parametric oscillator (OPO) developed at Stanford, will assist NASA in completing its trace-gas-detection objectives by supplying NASA with a critical, difficult-to-obtain laser source suitable for continuous-wave (cw) spectroscopy. During Phase I, LGR and Stanford will manufacture a monolithic OPO crystal, using techniques established by Stanford, generating between 1-2 W of single-frequency radiation between 3.2-3.4 um. At the end of Phase I, the OPO system will be used to measure transmission through a 50-cm-long methane cell (manufactured by LGR) at wavelengths corresponding to the C-H stretch vibrational resonance, 3.3 um. Technology readiness level (TRL) 4 will be reached at the completion of Phase I. During Phase II, remote detection of methane will be performed using a methane cell and measuring the backscattered light from the cell as the OPO mid-IR frequency is scanned ~5 GHz. The size of the housing for the monolithic OPO will be designed to reduce the overall size and weight of the mid-IR-laser head. Fiber-coupling for the incoming pump and the outgoing mid-IR radiation will be added to the OPO housing enabling simple fiber delivery. Modeling of the system sensitivity in ppm of methane will be performed for the final remote sensing system for ground-, air-, and space-based operation.