Megahertz opto-mechanical modulator

In this paper a Fabry-Perot modulator fabricated by surface micromachining is presented. The modulator is optimized for a wavelength of 1.3 mu m and intended for fiber-in-the-loop applications. It consists of a double-supported polysilicon beam separated from an underlying polysilicon electrode by an air gap. The two polysilicon electrodes form the mirrors of the Fabry-Perot cavity, By electrostatic actuation the optical path between the mirrors can be reduced, which results in modulation of the reflectivity. Characterization of the modulator shows a maximum on-off ratio of 9 dB. The observed modulator behavior indicates a maximum modulation rate of 2.8 Mbit s(-1).