We report an observation of essentially full spatial coherence in a high average power soft-x-ray laser. Rapid coherence buildup due to strong refractive antiguiding in a long plasma column is experimentally demonstrated. This allows the generation of fully coherent, milliwatt-level average power soft-x-ray radiation by a tabletop device. The peak brightness of this laser reaches within 0.01% spectral bandwidth, making it one of the brightest soft-x-ray sources available.
- Received 21 July 2000
- Published 5 February 2001
© 2001 The American Physical Society