Coupling light into planar thin-film waveguide - using evanescent field of auxiliary waveguide pressed against coating-free planar waveguide

摘要

Light is coupled into the planar waveguide (2), which consists of a thin, light conducting film, using the evanescent field of an auxiliary waveguide (4) which is brought into press contact with the uncoated planar waveguide. The auxiliary waveguide has no coating or casing in the region of press contact with the planar waveguide. The light to be coupled in is fed into the auxiliary waveguide via an optical fibre whose cladding is partially removed in the input region to uncover the core. USE/ADVANTAGE - For use in chemical or biological analysis, without precise requirements for positioning the optical elements, and exchange of thin waveguide films can be carried out by unskilled personnel.