A wide bandwidth, high sensitivity optical accelerometer having a lever arm to amplify the mechanical displacement of the accelerometer mass element. The optical accelerometer includes a high resonant-frequency spring-mass system, wherein the acceleration forces up to several hundred Hz cause a linear displacement of the mass with force, which, through the lever arm, modulates the intensity of a beam of light with a large gain. The modulated light beam is in turn converted to an electrical signal which corresponds to the applied accelerating force. The accelerometer of the present invention may be largely fabricated from a single piece of material such as silicon, wherein the lever, mass, spring and supporting structure are etched from a single substrate according to known photolithographic processes. Alternatively, the accelerometer components may be molded from a sheet plastic or other material. The accelerometer herein described provides a desired wide bandwidth and high sensitivity characteristic, and may be economically and accurately fabricated according to known manufacturing techniques.