Effects of threephoton absorption on nonlinear directional coupling.
The effects of three-photon absorption on nonlinear directional coupling in semiconductors below half the gap are studied for both cw and sech(2) pulse signals. The figure of merit associated with three-photon absorption includes not only material properties but also device design parameters. Numerical results show that at high powers, three-photon absorption significantly degrades nonlinear coupling, reduces throughput, and distorts output pulses. Good agreement is found between the theoretical model and experimental data.
C C
CC
Yang
A
A
Villeneuve
G I
GI
Stegeman
J S
JS
Aitchison