Photoconductive optically driven deformable membrane for spatial light modulator applications utilizing GaAs and InP substrates

Abstract

The fabrication and characterization of an optically addressable deformable mirror for spatial light modulator is described. Device operation utilizes an electrostatically driven pixellated aluminized polymeric membrane mirror supported above an optically controlled photoconductive GaAs substrate. A 5-µm thick grid of patterned photoresist supports the 2-µm thick aluminized Mylar™ membrane. A conductive ZnO layer is placed on the backside of the GaAs wafer. Similar devices were also fabricated with InP. A standard Michelson interferometer is used to measure mirror deformation data as a function of illumination, applied voltage and frequency. A simplified analysis of device operation is also presented.

Silicon based photo-controlled deformable mirror

“…PCDMs have been manufactured using crystalline inorganic photoconductors such as Gallium Arsenide (GaAs), Indium phosphide (InP) [20], Bismuth-Silicon-Oxyde (BSO) [17][15], Zinc Selenide (ZnSe) [21] and, more recently, using an organic photoconductor consisting in a mixture of P3HT/PCBM doped with an arylamine (m-MTDATA) dispersed in a polystyrene matrix [22]. A model which identifies the key parameters that affect their performances is reported in the literature [15].…”