0000000000252857
AUTHOR
K.w.h. Foulds
Silicon resonator sensors: interrogation techniques and characteristics
Interferometric and noninterferometric optical-fibre sensing systems for resonator vibrations are described. The quality factor variation with pressure, the temperature dependence of resonant frequency and the acceleration sensitivity are given for a double-ended tuning-fork based acceleratometer.
Nonlinear vibrations and hysteresis of micromachined silicon resonators designed as frequency-out sensors
Experimental observation of nonlinear vibrations and hysteresis of micromachined silicon resonators is reported. The experimental results are explained using a simple model in which the restoring force acting in the resonator contains a small cubic term. The effects will impose a limit to the maximum amplitude which can be excited while still maintaining reliability of these devices as frequency-out sensors.
Sensor Applications Of Optical Fibre Resonant Rings Based On Polarisation Sensitive Couplers
Optical fibre resonant rings based on polarisation sensitive couplers give rise to a set of new resonant configurations. Two of them exhibit interesting sensor applications since small changes of the polarisation state produce large effects on the output, due to the resonant characteristics of the system. The sensor arrangements proposed have the advantage of requiring no drift compensation of the optical fibre interferometer against environmental fluctuations, since the parameters used to determine the measurand are the finesse and the visibility but not a phase change. Thus, the system can be used to sense low frequency measurands. Among the particular sensor applications that can be sugg…
Optical activation of a silicon vibrating sensor
The operation of a micromachined silicon vibrating sensor with both optical excitation and optical interrogation is reported. The proper locations at which the optical excitation should be applied for optimum excitation of different modes of resonance are described.
Analysis of an interferometric optical fibre detection technique applied to silicon vibrating sensors
A simple and accurate analysis of a single-mode optical fibre interferometric displacement detection technique is resented. This analysis is in good agreement with experimental measurements, and shows that angular alignment between the fibre and the sensor is the most critical parameter.
Sensitivity and mode spectrum of a frequency-output silicon pressure sensor
The vibrational mode spectrum of a silicon vibrating pressure sensor is investigated. Particular attention is given to the analysis of the vibration shapes, quality factors and relative sensitivity of the resonance frequencies as a function of pressure. It is shown that a pressure sensitivity of a few parts per million at one atmosphere can be achieved. Some comments are also made regarding an improved design of the device.