We demonstrate a novel technique for coupling extreme-ultraviolet (XUV) harmonic radiation out of a femtosecond enhancement cavity. We use a small-period diffraction grating etched directly into the surface of a dielectric mirror. For the fundamental light, this element acts as a high reflector. For harmonic wavelengths, it acts as a diffraction grating, coupling XUV radiation out of the cavity. Using this method, we observed the third through twenty-first odd harmonics with a dramatic increase in usable power over previous results of high-harmonic generation at high repetition rates.
© 2008 Optical Society of America
Original Manuscript: March 11, 2008
Manuscript Accepted: April 8, 2008
Published: May 13, 2008
D. C. Yost, T. R. Schibli, and Jun Ye, "Efficient output coupling of intracavity high-harmonic generation," Opt. Lett. 33, 1099-1101 (2008)