Comparison of dc electric field and tapered wiggler free electron laser efficiency enhancement schemes
Abstract
A constant parameter wiggler free electron laser using a dc electric field for efficiency enhancement is compared to several tapered wiggler efficiency enhancement schemes. Analytical expressions for the efficiency in the plane wave, infinitesimally small radius electron beam limit are derived and compared. Numerical simulations for a Gaussian radiation field and finite radius electron beam with an output radiation wavelength of 2 microns are presented. For finite radius electron beams, the extraction efficiency using a dc electric field is somewhat greater than or equal to that using proposed tapering schemes. While the dc field offers flexibility in efficient, tunable laser design, the required field strengths for visible radiation are in the megavolt/meter range.
 Publication:

IEEE Journal of Quantum Electronics
 Pub Date:
 July 1985
 DOI:
 10.1109/JQE.1985.1072750
 Bibcode:
 1985IJQE...21..998B
 Keywords:

 Amplification;
 Electric Fields;
 Free Electron Lasers;
 Laser Outputs;
 Power Efficiency;
 Wiggler Magnets;
 Direct Current;
 Electron Beams;
 Electron Energy;
 Electron Mobility;
 Energy Spectra;
 Lasers and Masers