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Ringresonator-Sensor

Method of detecting molecules and optical sensor
 
: Heidrich, H.; Lützow, P.; Pergande, D.; Schade, W.

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Frontpage ()

EP 20110075072 A: 20110421
Englisch
Patent, Elektronische Publikation
Fraunhofer HHI ()

Abstract
The invention relates to a method for detecting molecules of a particular substance by means of an optical sensor. This method comprises the steps of - bringing the sensor into contact with a fluid to be analyzed, - coupling light of a first wavelength ( 1 ) into an optical resonator (3) of the sensor, the resonator (3) being covered at least partially with an active layer of a covering material for selectively adsorbing a group of substances, - coupling light of a second wavelength ( 2 ) into the same resonator (3) or into a second optical resonator (3') of the sensor, the second resonator (3') being covered at least partially with an active layer of the same covering material - detecting, for each of the first and the second wavelength ( 1 , 2 ), an optical signal coupled out of an optical path containing the respective resonator (3, 3'), - varying an optical length of the respective resonator (3, 3') or the respective wavelength ( 1 , 2 ) such that an interval comprising at least one resonance of the respective resonator (3, 3') is scanned, and - detecting a broadening of this resonance indicating an absorption of the light fed into the respective resonator (3, 3') by molecules accumulated at the active layer of this resonator (3, 3'). The invention also relates to an optical sensor designed for performing this method.

: http://publica.fraunhofer.de/dokumente/N-225222.html