MICROFLUIDIC chip for spectroscopic and refractometric analysis

In this paper an optofluidic chip for simultaneous determination of refractive index and acquisition of absorption or fluorescent spectra is described. The system comprises a microfluidic channel with multiple inlet/outlet for sample handling and a dual fiber optic probe, standing face to face across the channel, for the optical measurements. An FBG based Fabry Perot cavity, and a Braggmeter, allow for interferometric measurement of the refractive index while external illumination and a multimode fiber enable acquisition of the absorption/fluorescence spectra with a CCD spectrometer. Preliminary results showing the viability of simultaneous measurement are obtained from the characterization of mixed samples with distinct refractive index and dye concentrations.