High Power Single Frequency Source for Cavity Ring-Down Spectroscopy

NIST is using a sensitive optical technique called cavity ring-down detection to permit detection of impurities in semiconductor process gases, which cause substantial losses in manufacturing yield. In order to increase the sensitivity and range of application of this technique, improved single frequency laser sources are required. In particular, lasers providing more power, narrower line-width, better beam quality and access to a wider range of wavelengths would allow detection of a wider range of species with greater sensitivity. Aculight has developed a novel laser technology which meets all of these requirements. As a final result of this program, we will deliver a packaged, fiber-based laser system which provides 1 Watt of tunable, single frequency output between 1.6 and 1.8 um. This is two orders of magnitude more power than diode lasers currently used for the application. In order to verify the utility of the laser for the application we will show that greatly increased efficiency of coupling into a ring-down cavity can be demonstrated when compared with that observed with diode laser. COMMERCIAL APPLICATIONS: Single frequency sources in the near to mid-infrared have a wide range of applications in trace gas detection for environmental and industrial process monitoring, gas leak detection, combustion diagnostics, telecom test and measurement, and laboratory spectroscopy. We propose to initially develop these sources as laboratory scientific lasers comparable to tunable diode lasers, but with much greater power and wavelength access. Further development of such sources for low cost and compact packaging will allow their use in sensor applications.