A proposal and a demonstrational study of an electrostatically driven surface output optical switching device with a sheet waveguide

An electrostatically driven surface output optical switching device with a sheet waveguide is proposed. The device mainly consists of two optical parts, that is an optical glass substrate to propagate the incident light and an electrostatic movable Ta2O5 cantilever to transfer light energy from the substrate to free space. When the voltage is applied, the cantilever is attracted and contacts to the substrate. By the contact, light energy transfered from the substrate to the cantilever is scattered by the diffusive surface on the Ta2O5 cantilever resulting in the optical switching. The device is fabricated by using micro-machine techniques to demonstrate the principle. A diffusive surface on the cantilever is fabricated by an RIE etching. Switching operations are demonstrated. As a result, modulated light amplitudes are observed from diffusive surface on the cantilever according to the voltage change. A switching contrast of 0.75 and an extinction ratio of 8dB are obtained at a driving frequency of 60Hz. It is shown that the device can be usefulness for optical switching. Also, it is considered that the device can be applied to a display device when the device is integrated on the substrate.