Generation of microjoule coherent extreme-ultraviolet light using high-order harmonics

Abstract

The energy scaling of high-order harmonics in Ar and Xe gases under the phase-matched condition was investigated. In argon gas, a total output harmonic energy as high as 0.7 microjoule was obtained in the spectral region of 34.8 to 25.8 nm (the corresponding order of the 23rd to 31st harmonic), while the maximal 27th harmonic (29.6 nm) energy attained was as high as 0.32 microjoule with an almost perfect spatial profile. In addition, the generation of 10 microjoule coherent extreme-ultraviolet (XUV) light at wavelengths between 73.6 to 42.6 nm (the corresponding order of the 11th to 19th harmonic) was demonstrated in Xe gas. The peak power of this coherent XUV light was estimated to be 0.13 GW at the 13th harmonic (62.3 nm), and the peak brightness achieved was 3 x 10(exp 28) photon/mm(exp 2)/mrad(exp 2)/s.