Grating-assisted phase matching in extreme nonlinear optics.
We propose a new technique for phase matching high harmonic generation that can be used for generating bright, tabletop, tunable, and coherent x-ray sources at keV photon energies. A weak quasi-cw counterpropagating field induces a sinusoidal modulation in the phase of the emitted harmonics that can be used for correcting the large plasma-induced phase mismatch. We develop an analytical model that describes this grating-assisted x-ray phase matching and predicts that very modest intensities (<10(10) W/cm2) of quasi-cw counterpropagating fields are required for implementation.
Cohen
Oren
O
Department of Physics and JILA, University of Colorado at Boulder and NIST, Boulder, Colorado 80309, USA. oren.cohen@colorado.edu
Zhang
Xiaoshi
X
Lytle
Amy L
AL
Popmintchev
Tenio
T
Murnane
Margaret M
MM
Kapteyn
Henry C
HC