| Stand Off Detection | |
|---|---|
 |
An ultrashort high-energy laser pulse propagating through a medium can result in a white light filament. A white light filament is an extended low-density plasma channel ~100 µm in diameter with an intensity of ~1013 W/cm2. In air, this filament can extend for several kilometers. One characteristic of this plasma channel is its broadband spectrum (visible to IR, with an input pulse of 800 nm). Many research groups are investigating the use of the filament for broadband detection of atmospheric constituents. In our research, we have used genetic algorithm/pulse shaping technology to control where in a water tank a filament begins and how long the filament propagates. Current research includes using the genetic algorithm/pulse shaping technology and the broad spectrum of the filaments to elicit a signal characteristic to certain chemical compounds. |