title: Fibre optic coupler as a detector for microfluidic applications.
abstract: A new construction of a fibre optic coupler is presented in the paper. Two polymer optical fibres were used to build a coupler in which coupling efficiency of optical power depends on the refractive index of liquid delivered to a microchannel formed by the fibres. The coupler was tested as a detector in saccharose concentration measurements, and was used in absorbance measurements. A red light emitting diode and a spectrometer were used as a light source and a photodetector, respectively. Experiments confirmed that the coupler can be used for the real time monitoring of the changes in the refractive index of a saccharose solution exhibiting repeatable changes in the signal, with no hysteresis. Absorbance tests were performed with a solution of bromothymol blue at different pH.
authors.affiliation: Warsaw University of Technology, Department of Analytical Chemistry, Noskowskiego 3, 00-664 Warsaw, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Stadnik
authors.forename: Artur
authors.initials: A
authors.lastname: Dybko