2-STATE ELECTRICALLY CONTROLLABLE PHASE DIFFRACTION GRATING USING ARRAYS OF VERTICAL-CAVITY PHASE FLIP MODULATORS

An electrically controlled, two state, phase modulated diffraction gra ting is created by fabricating a vertical-cavity phase flip modulator and etching the top of the structure into a series of stripes. The mod ulator switches phase between 0 and 180 degrees with 7-V bias, Alterna ting stripes are electrically isolated from the switching voltage as a result of stripe etching. With zero bias, the etched device reflects all normally incident light normal to the device. With bias, the light is diffracted primarily into the first-order diffraction peaks. We de monstrate this device, depict the parasitic effects of etching, and sh ow the device design limitations.