A new spatial light modulator that uses electroabsorption induced by the Franz–Keldysh effect in a GaAs single crystal is proposed. The device has the same structure as the Pockels readout optical modulator, is driven by a high ac voltage, and is operated in the superprime mode. Its high-frame-rate (over 500-Hz) operation, high contrast ratio (350:1), and large γ characteristics (2.47) were experimentally confirmed in the transmission mode, although its operating-wavelength (readout) region is restricted to a narrow band near the band gap. In the reflection mode, however, this device has a high contrast ratio and large γ characteristic (approximately 5), offering the possibility of its use as a nonlinear device.
© 1998 Optical Society of America
(230.6120) Optical devices : Spatial light modulators
Original Manuscript: May 22, 1997
Revised Manuscript: November 10, 1997
Published: March 10, 1998
Youichi Bitou, Hiroki Ohta, and Takumi Minemoto, "High-speed and high-contrast spatial light modulator that uses electroabsorption in a GaAs single crystal," Appl. Opt. 37, 1377-1385 (1998)