PHOTOTHERMAL EXCITATION AND SELF-EXCITATION OF SILICON MICRORESONATORS

Fiber-optic sensors with a silicon microresonator acting as a sensitive element have been proposed for measurement of many physical parameters. The basic principle is that the measured value changes the resonance frequency of the microresonator. The flexural vibrations of the microresonator are excited photothermally under the action of modulated optical radiation. The interferometric optical feedback may cause self-oscillation of the microresonator even without light modulation. This is a theoretical paper devoted to consideration of the effects of photothermal excitation and self-excitation of silicon microresonators. For the first time the mechanism of parametric excitation of microresonators is investigated. The temperature compensation techniques are analyzed.