Fabrication and characterization of a liquid core integrated interferometer

We report the feasibility and the characterization of a microfluidic Mach-Zehnder (MZ) interferometer. Unlike the conventional MZ interferometer based on solid core, in our MZ configuration the light is confined inside a low refractive index liquid core by antiresonant reflecting optical waveguide (ARROW). So, the refractive index of the device core can be easily changed by replacing the fluid within it. We have demonstrated the operation of such device by measuring the spectrum of optical power transmitted from two different MZ configurations. The results show that interferometers with a good visibility can be achieved in good agreement with the theoretical results.