| 摘要 |
The present invention relates to an assembly and method for measuring the optical activity of a stimulus of interest. The assembly comprises a source of incident electromagnetic radiation ( 1 ), a lens arrangement ( 2 ), an input polariser ( 3 ), a planar waveguide structure ( 4 ) (or an optical fiber), an output polariser ( 5 ), a lens arrangement ( 6 ) for focussing the output electromagnetic radiation and a detector. The polarisation of the incident electromagnetic radiation relative to the planar waveguide structure ( 4 ) is determined by the input polariser ( 3 ). The planar waveguide structure in this embodiment comprises a silicon substrate layer ( 4 c) and an absorbent layer ( 4 e). The silicon oxynitride layer ( 4 c) acts as the reference waveguide and the absorbent layer ( 4 e) acts as the sensing waveguide. The sensing waveguide ( 4 e) is exposed in the localised environment ( 8 ) to a smaple containing the stimulus of interest which is optically active. The adjusted attitude of the output polariser ( 5 ) is directly proportional to the optical activity the stimulus of interest.
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