A Photomicrodynamic System with a Mechanical Resonator Monolithically Integrated with Laser Diodes on Gallium Arsenide

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Science  07 May 1993:
Vol. 260, Issue 5109, pp. 786-789
DOI: 10.1126/science.260.5109.786


A cantilever resonant microbeam, laser diodes, and a photodiode have been fabricated on the surface of a gallium arsenide substrate. The microbeam is excited photothermally by light from a laser diode. The vibration is detected with a photodiode as the variation in light output caused by the difference in optical length between the microbeam and another laser diode. A high carrier-to-noise ratio (45 decibels) is achieved with a short (3 micrometers) external cavity length. Such a small distance allows a lensless system, which increases the ease of fabrication. This work could lead to applications in which photomicrodynamic systems are monolithically integrated on a gallium arsenide substrate with surface micromachining technology.