From Shadowgraph to Monochromatic Schlieren: Time-Resolved Imaging of Dim Laser-Induced Phenomena in the Presence of Saturating Plasma Emission
- UAH Laser Propulsion Group, University of Alabama in Huntsville, Physics Department, OB-201B John Wright Dr., Huntsville, AL (United States)
Plasma emission generated during a laser ablation event can saturate an imaging system, washing out valuable information about non-luminous features such as vapor plumes and shock waves. A step-by-step experimental history of development of imaging system from Shadowgraph to Monochromatic Schlieren is presented here as a method of resolving this issue. An ICCD system was used to image ablation events on {mu}s-timescales in combination with a fiber-coupled Nd:YAG laser operating at a primary output of 50 mW at 532 nm wavelength, which was used as the illumination source. A monochromatic band pass filter at 532{+-}10 nm was inserted into the Schlieren system between the focusing lens and the spatial filter, producing a minute shift in the Schlieren focus. With the filter, the saturation effects were eliminated and features such as shock waves and vapor plumes were clearly visible even when plasma was present. Issues with implementation of this system for application to the study of laser propulsion are discussed in detail.
- OSTI ID:
- 21137096
- Journal Information:
- AIP Conference Proceedings, Vol. 997, Issue 1; Conference: 5. international symposium on beamed energy propulsion, Kailua-Kona, HI (United States), 12-15 Nov 2007; Other Information: DOI: 10.1063/1.2931883; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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