A miniature Fabry-Perot interferometer fabricated using silicon micromachining techniques

The techniques of silicon micromachining have been used to fabricate a miniature Fabry-Perot interferometer for use in the near infrared spectral region. The device consists of two silicon wafers with deposited, highly reflective dielectric mirrors. The wafers are bonded together with a small gap between the mirrors, and sawed into individual devices. The wavelength tuning and parallelism control of the mirror elements are achieved electrostatically, by varying the voltage between control electrodes. The measured finesse of the structure exceeds 90 at a wavelength of 1.4 mu m, resulting in a FWHM optical bandwidth of 3.1 nm. These devices are expected to find application as laser intercavity elements, wavelength demultiplexers in fiber optic telecommunications system, and as sensors of pressure and acceleration.<>