TY - JOUR
T1 - Phase matching of high harmonic generation in the soft and hard X-ray regions of the spectrum
AU - Popmintchev, Tenio
AU - Chen, Ming Chang
AU - Bahabad, Alon
AU - Gerrity, Michael
AU - Sidorenko, Pavel
AU - Cohen, Oren
AU - Christov, Ivan P.
AU - Murnane, Margaret M.
AU - Kapteyn, Henry C.
PY - 2009/6/30
Y1 - 2009/6/30
N2 - We show how bright, tabletop, fully coherent hard X-ray beams can be generated through nonlinear upconversion of femtosecond laser light. By driving the high-order harmonic generation process using longer-wavelength midinfrared light, we show that, in theory, fully phase-matched frequency upconversion can extend into the hard X-ray region of the spectrum. We verify our scaling predictions experimentally by demonstrating phase matching in the soft X-ray region of the spectrum around 330 eV, using ultrafast driving laser pulses at 1.3-μm wavelength, in an extended, high-pressure, weakly ionized gas medium. We also show through calculations that scaling of the overall conversion efficiency is surprisingly favorable as the wavelength of the driving laser is increased, making tabletop, fully coherent, multi-keV X-ray sources feasible. The rapidly decreasing microscopic single-atom yield, predicted for harmonics driven by longer-wavelength lasers, is compensated macroscopically by an increased optimal pressure for phase matching and a rapidly decreasing reabsorption of the generated X-rays.
AB - We show how bright, tabletop, fully coherent hard X-ray beams can be generated through nonlinear upconversion of femtosecond laser light. By driving the high-order harmonic generation process using longer-wavelength midinfrared light, we show that, in theory, fully phase-matched frequency upconversion can extend into the hard X-ray region of the spectrum. We verify our scaling predictions experimentally by demonstrating phase matching in the soft X-ray region of the spectrum around 330 eV, using ultrafast driving laser pulses at 1.3-μm wavelength, in an extended, high-pressure, weakly ionized gas medium. We also show through calculations that scaling of the overall conversion efficiency is surprisingly favorable as the wavelength of the driving laser is increased, making tabletop, fully coherent, multi-keV X-ray sources feasible. The rapidly decreasing microscopic single-atom yield, predicted for harmonics driven by longer-wavelength lasers, is compensated macroscopically by an increased optimal pressure for phase matching and a rapidly decreasing reabsorption of the generated X-rays.
KW - Coherent
KW - Extreme nonlinear optics
KW - Ultrafast
UR - http://www.scopus.com/inward/record.url?scp=67649817156&partnerID=8YFLogxK
U2 - 10.1073/pnas.0903748106
DO - 10.1073/pnas.0903748106
M3 - 文章
C2 - 19541611
AN - SCOPUS:67649817156
SN - 0027-8424
VL - 106
SP - 10516
EP - 10521
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 26
ER -