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Development of a two photon/laser induced fluorescence technique for the detection of atmospheric oh radicals
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Bradshaw, John |
| Copyright Year | 1990 |
| Description | The development of a new mid-IR laser source was the primary goal. Backward propagating stimulated D2 Raman frequency down conversion of a commercially available 1.06 micron Nd:YAG laser was shown to generate an efficient source of 1.56 micron radiation with near diffraction limited beam quality. The efficient generation of a 2.9 micron laser source was also achieved using backward propagating CH4 Raman frequency down conversion of the 1.56 micron pump. Slightly higher efficiencies were obtained for frequency down conversion of the 1.06 micron Nd:YAG using the H2 Raman shift yielding a near diffraction limited source in the 200 mJ range at 1.9 micron. Similar conversion efficiencies are anticipated as a result of extending the wavelength coverage of recently available Ti:sapphire pulse laser to not only cover the 740 to 860 nm fundamental wavelength range but also the .95 to 1.15 and 1.06 to 1.33 micron range using D2 and H2, respectively. The anticipated sensitivity of a TP-LIF OH sensor using this mid-IR source would give signal limited detection of 1.4 x 10(exp 5) OH/cu cm under boundary layer conditions and 5.5 x 10(exp 4) OH/cu cm under free troposphere sampling conditions for a five minute signal integration period. This level of performance coupled with the techniques non-perturbing nature and freedom from both interferences and background would allow reliable tropospheric OH measurement to be obtained under virtually any ambient condition of current interest, including interstitial and sampling. |
| File Size | 746153 |
| Page Count | 12 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19910006216 |
| Archival Resource Key | ark:/13960/t0dv6fh5x |
| Language | English |
| Publisher Date | 1990-01-01 |
| Access Restriction | Open |
| Subject Keyword | Lasers And Masers Methane Raman Spectra Laser Outputs Frequency Converters Yag Lasers Troposphere Laser Induced Fluorescence Pulsed Lasers Functional Design Specifications Down-converters Diffraction Hydroxyl Radicals Infrared Radiation Boundary Layers Signal Detection Neodymium Lasers Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
