Room Temperature Mid-IR Laser Source

The AF needs compact, portable sources of tunable infrared radiation for spectroscopic gas detection. Devices incorporating these sources can be used for measuring the efficiency of combustion in jet engines, measuring the spectroscopic signatures of combustion gases in high-temperature test cells, and monitoring environmentally sensitive engine emission gases. Many of the most important molecules, including hydrocarbons, have strong fundamental absorptions in the 3 micron wavelength region. Existing infrared sources suffer from several deficiencies. Pulsed optical parametric oscillators are too large and costly. Lead-salt lasers have low output power and require cryogenic cooling. Room-temperature diode lasers in this wavelength region are now under development, but reliable devices with sufficiently wide tuning ranges will not be avialable for many years. Our innovation is an alternative light source: an integrated grequency converted, pumped by diode lasers. In this device, several of the functions now performed by discrete bulk optical components are combined for the first time on a single chip. During Phase I we will build and demonstrate a prototype integrated frequency converter. In Phase II we will produce and deliver a compact light source incorporating the proposed converter to the Air Force for use in combustion research.