Control of laser high-harmonic generation with counterpropagating light.
Relatively weak counterpropagating light is shown to disrupt the emission of laser high-harmonic generation. Harmonic orders ranging from the teens to the low thirties produced by a 30-femtosecond pulse in a narrow argon jet are "shut down" with a contrast as high as 2 orders of magnitude by a chirped 1-picosecond counterpropagating laser pulse (60 times less intense). Alternatively, under poor phase-matching conditions, the counterpropagating light boosts harmonic production by similar contrast through quasiphase matching where out-of-phase emission is suppressed.
Voronov
S L
SL
Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, USA.
Kohl
I
I
Madsen
J B
JB
Simmons
J
J
Terry
N
N
Titensor
J
J
Wang
Q
Q
Peatross
J
J