We demonstrate that effective traveling-wave excitation of high-gain amplifiers requires velocities that are remarkably slower than the velocity of light. Experiments with a femtosecond-laser-pumped molecular hydrogen laser exhibit pronounced enhancement of the intensity if an excitation velocity that is slower than the velocity of light is employed. These results are directly scalable to shorter wavelengths, paving the way for a more effective pump setup for x-ray lasers.
© 2001 Optical Society of America
(140.3280) Lasers and laser optics : Laser amplifiers
(140.3430) Lasers and laser optics : Laser theory
(140.3460) Lasers and laser optics : Lasers
(140.7240) Lasers and laser optics : UV, EUV, and X-ray lasers
Riccardo Tommasini and Ernst E. Fill, "Effective traveling-wave excitation below the speed of light," Opt. Lett. 26, 689-691 (2001)