Real-time, compact, laser absorption-based sensors for trace gas detection have been developed. Difference-frequency generation in a periodically poled lithium niobate (PPLN) crystal pumped by two compact lasers, a near-infrared diode laser and a monolithic ring Nd:YAG laser, is used as a mid-infrared laser source. Detection of carbon monoxide (CO) and formaldehyde $\rm (H\sb2CO)$ in ppm to sub-ppm level has been performed, based on a direct absorption spectroscopy. The portable sensor designed for monitoring the CO concentration in ambient air was built and operated in the laboratory, in the open air, and a test chamber located at the NASA Johnson Space Center.
| Identifer | oai:union.ndltd.org:RICE/oai:scholarship.rice.edu:1911/17110 |
| Date | January 1997 |
| Creators | Mine, Yasuharu |
| Contributors | Tittel, F. K. |
| Source Sets | Rice University |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | 72 p., application/pdf |
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