Description: This proposal addresses, for the first time, the demonstration of integrated mid-infrared sources based on waveguiding in a bonded solid-state laser material and periodically poled nonlinear material. A focused femtosecond laser beam allows for precisely localized modification of the refractive index of a material, therefore enabling to create waveguiding structures. The offeror has demonstrated femtosecond-laser-inscribed singlemode waveguide in Nd:YAG with record-low propagation loss of 0.2dB/cm. The inscription technique was optimized by their comprehensive numerical modeling ability. A single continuous waveguide will be inscribed in a laser-bonded Nd:YAG substrate and a periodically poled crystal, then integrated with a tunable laser in the near infrared. The resulting small mode size leads to efficient lasing in the laser material and efficient difference frequency generation via nonlinear wavemixing in the periodically poled element. This will enable the manufacturing of compact, tunable, mid-infrared laser sources with excellent spectral and spatial quality and low size, weight and power for NASA and non-NASA applications.The targeted range of wavelengths, between 3 and 5 micrometers, corresponds to absorption lines of several functional groups, and the tunable monochromatic mid-infrared source can therefore be integrated in a large range of instruments that monitor species such as formaldehyde, methane, ethylene, carbon and nitrogen oxides, by absorption spectroscopy. The developed architecture is also compatible with sum-frequency generation, allowing the development of tunable sources in the visible. The proposed technology enables the ultimate 3D fabrication of integrated photonics circuits via combining passive and active media such as waveguide lasers, detectors, modulators, and optical interconnects. The offeror has attracted $2.3 million financial commitment from Coherent, Toptica, etc for joint development/support of the proposed technology.

Benefits: Realtime monitoring of formaldehyde, a health hazard, for long-duration inhabited space missions Monitoring of formaldehyde in the atmosphere for climate studies Monitoring of methane, carbon and nitrogen oxides in the atmosphere for pollution and climate studies

Monitoring of indoor & outdoor pollution, e.g., formaldehyde. Monitoring of healthhazardous species, e.g., chemical/biological warfare Monitoring of combustion and pollution sources for climate studies and industrial processes, e.g, methane, carbon and nitrogen oxides Biomedical applications, e.g., noninvasive breath analysis of ethylene and large biomarker molecules for disease assessment.