A Theory for Optical Wavelength Control in Short Pulse Free Electron Laser Oscillators
Abstract
The future safety of the U.S. Navy warship depends on the development of a directed energy self-defense system to keep pace with the ever-improving technology of anti-ship missiles. Two candidates are reviewed. The free electron laser (FEL) has the most advantages, but a chemical laser proposed by TRW is ready for installation on existing ships. Initial testing of issues related to directed energy use at sea can be conducted with the chemical laser. When the technology of the FEL matures, it can replace the chemical laser to provide the best possible defense in the shortest period of time. Continuous tunability is a key advantage of the FEL over the conventional laser. But since the output wavelength is dependent on electron energy. It is subject to random fluctuations originating from the beam source. At the Stanford University Superconducting (SCA) Free Electron Laser (FEL) Facility, the effects are minimized through negative feedback by changing the input electron energy proportional to the observed wavelength drift. The process is simulated by modifying a short pulse FEL numerical program to allow the resonant wavelength to vary over many passes. The physical effects behind optical wavelength control are explained. A theory for the preferential nature of the FEL to follow the resonant wavelength from longer to shorter wavelengths is presented. Finally, the response of the FEL to a rapidly changing resonant wavelength is displayed as a transfer function for the system. FEL, Free electron laser, Short pulse simulation, Optical wavelength control, Trapped particle, Instability, Desynchronism, Mode competition, Low gain FEL, Resonance condition, Wavelength stabilization, FEL transfer function, Directed energy at sea.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1993
- Accession Number
- ADA271706
Entities
People
- Wade F. Wilkenson
Organizations
- Naval Postgraduate School