All-optical spatial light modulator with megahertz modulation rates.
We demonstrate a novel all-optical spatial light modulator capable of megahertz modulation rates. It is based on the quantum-confined Stark effect, but the modulating electric field is entirely photogenerated by strongly asymmetric photocarrier transfer in GaAs/AlAs layers. In a nonoptimized sample, cw optical excitation of approximately 50 W/cm(2) created a 30-kV/cm electric field, inducing a 9-meV exciton red shift at room temperature. Under pulsed excitation the photogenerated electric field can be switched on in a few tens of picoseconds and relaxes in a few hundred nanoseconds, permitting megahertz modulation rates.
N T
NT
Pelekanos
B
B
Deveaud
J M
JM
Gérard
H
H
Haas
U
U
Strauss
W W
WW
Rühle
J
J
Hebling
J
J
Kuhl