Optical resonator for sensor arrangement and measuring method

摘要

A sensor arrangement including a light source, a first optical element, a second optical element, a first photo detector, and a second photo detector. The light source is optically coupled to the first optical element that is optically coupled to the second optical element. The first photo detector is optically coupled to the first optical element for detecting a first component of the part of the light which is not transmitted by the second optical element, and the second photo detector is optically coupled to the second optical element for detecting a second component of the part of the light which is transmitted by the second optical element. One of the first and the second optical elements is an optical filter and the other is a sensor element, where the sensor element or the filter is tunable.

主权项

1. An optical sensor arrangement for measuring an observable, comprising:
a light source for emitting light of a spectrum containing a plurality of different wavelengths; a first optical element; a second optical element; a first photo detector; a second photo detector; and a control unit,
wherein the light source is optically coupled to the first optical element for feeding the light into the first optical element, the first optical element being optically coupled to the second optical element for feeding a part of the light transmitted by the first optical element into the second optical element,wherein the first photo detector is optically coupled to the first optical element for detecting a first component of said part of the light which is not transmitted by the second optical element, the second photo detector being optically coupled to the second optical element for detecting a second component of said part of the light which is transmitted by the second optical element,wherein one of the first and the second optical elements is an optical filter for filtering out a subset of said wavelengths, a transmittance of the filter showing at least one peak, the peak coinciding with one of said wavelengths, andwherein the remaining of the first and the second optical elements is a sensor element, the sensor element being an optical resonator, an optical length of this resonator being variable depending on the observable,the sensor element or the filter being tunable,wherein the control unit is configured for tuning the sensor element or the filter via a control signal, the control signal being adapted for shifting, dependent on output signals of the first and the second photo detectors, a resonance wavelength of the optical resonator or said peak such that the resonance wavelength and the peak are made to coincide, a strength of the shifting control signal being a measure for the observable.