Electromechanical devices can be used to rapidly modulate light if their mechanical inertias can be made small enough. The usefulness of these devices depends upon the ability to produce them in large arrays with high yield and at low cost, to integrate them with their drive circuitry, and to achieve a high level of reliability and reproducibility. In recent years micromechanical fabrication techniques have been used to produce arrays of miniature optical modula-tors on silicon that can operate at frequencies to 1 MHz with negligible drive power. They are completely compatible with integrated circuit technology and can be fabricated on a silicon wafer along with electronic circuits. In large arrays they can transfer data at a high rate for parallel optical readout of microelectronic devices and sensor arrays. Once in optical form, the data are amenable to optical processing. The development of the micromechanical modulator, its features, performance characteristics and limitations, and its potential applications to data transfer and processing are discussed.