Effect of counterintuitive time delays in nonlinear mixing.
The effect of varying the relative arrival time of the two laser pulses employed in doubly resonant four-wave sum mixing, enhanced by induced transparency, is studied with the aim of optimizing the efficiency of vacuum-ultraviolet generation. With atomic hydrogen as the nonlinear medium, pulsed radiation with wavelengths of 243 and 656 nm and durations of 8 and 14 ns, respectively, is mixed to generate 103-nm coherent radiation. It is shown that by delaying the arrival time of the ground-state pump beam (243 nm) by 2.5-3.5 ns relative to the arrival of the upper-state coupling beam (656 nm), it is possible to enhance the generated intensity by a factor of 2 or more.
R I
RI
Thompson
L
L
Marmet
B P
BP
Stoicheff