Microwave Energy Deposition and Control Using Ultrafast Lasers for Improving the Performance of High Speed Vehicles

The objective of this research is to determine if microwave energy deposition can be localized by laser or other means such that significant levels of power/energy can be delivered to off body locations for flow control applications. Preliminary work has shown that very low energy short pulse laser beams can localize microwave energy deposition. Many research questions remain, however, including the efficiency of that energy deposition, the length of time the deposition region remains stable, the potential for simultaneous or sequential multi point energy addition with the extrapolation to the designation of shaped regions for energy addition. During Phase I, Spectral Energies, LLC and Princeton University research team will establish laser pulse energy levels, pulse length and wavelength required for strong microwave coupling and the potential for shaped energy addition. Scaling of the coupling with microwave wavelength will be addressed theoretically based on the laboratory results using the high power sources in the 3 GHz regime. Extrapolation to 94 GHz will be of particular interest due to the availability of high power sources at that frequency and the ability to focus the microwave beam to high intensity due to the short wavelength. This research is of particular interest for the deposition of energy in front of bow shocks for maneuvering hypersonic vehicles and the creation of localized thermal regions for flow deflection. BENEFIT: The development of off surface energy addition is expected to lead to future research in flow control and will be of particular interest for the deposition of energy in front of bow shocks for maneuvering hypersonic vehicles and the creation of localized thermal regions for flow deflection. The interaction of microwaves with laser generated plasmas will also lead to methods for the guiding of microwaves over long distances. Military applications include long-range bombers, fighters, and unmanned aerial vehicles. Potential commercial applications include but not limited to high speed civil transport, space launch and reentry systems.