Two-state electrically controllable phase diffraction grating using arrays of vertical-cavity phase flip modulators

An electrically controlled, two state, phase modulated diffraction grating is created by fabricating a vertical-cavity phase flip modulator and etching the top of the structure into a series of stripes. The modulator switches phase between 0 and 180/spl deg/ with 7-V bias. Alternating 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 demonstrate this device, depict the parasitic effects of etching, and show the device design limitations.