Infrared frequency upconverter for high-sensitivity imaging of gas plumes

Abstract

A remote methane detection system has been developed using a single-frequency tunable optical parametric oscillator at 3.4 microm infrared wavelength. The infrared received light is converted by a frequency upconverter with a strong pump beam to near-infrared wavelength at 0.81 microm and detected by a sensitive photomultiplier. The conversion efficiency of the upconverter was 40% for the backscatter signal from a topographic target, and the detector sensitivity was 11 times higher than that of the cooled InAs detector. By raster scanning the infrared beam, imaging was realized for the methane gas plume with an accuracy of 20 parts in 10(6)m at the range of ~2m.

Tunable narrow linewidth laser source for a methane lidar

“…The development of a compact, reliable and high efficiency pulsed tunable source will be a major step toward space based trace gas remote sensing application. Many gas sensing lidar systems are based on optical parametric oscillator (OPO) [3][4][5][6][7]. Due to the optical feedback provided by the resonant cavity, OPO has low laser threshold.…”

Seeded nanosecond optical parametric generator for trace gas measurements

“…For MIR detectors for such flight demo, we are testing a HgCdTe array detector used in the Hubble Space Telescope and an infrared HgCdTe avalanche photodiode (APD). We are also building an upconversion detector, where 3μm is frequency up-converted to 0.8μm by a PPLN crystal pumped at 1064nm through a sum-frequency generation process [7]. The 0.8-μm light can be detected by an APD.…”

Upconversion detection of long-wave infrared radiation from a quantum cascade laser

“…Many substances can be identified by their spectral features associated with fundamental rotational and vibrational absorption bands in the infrared spectral region. This has spurred much attention to infrared (IR) technologies relating to applications, such as infrared spectroscopy [1][2][3][4] and infrared hyperspectral imaging [5][6][7][8]. Infrared spectroscopy has found applications within diverse fields like environmental gas monitoring [9,10] and medical applications e.g.…”