Lithium niobate optical sensing chip for portable instrument

In this paper, we demonstrated an optical lithium niobate sensing chip (LNSC) by integrating an optical waveguide phase modulator and an evanescent field-based waveguide sensor on the same chip. The repeatable phase measurements based on a homodyne metrology are achievable by injecting evaporative ethanol (concentration: 95%) liquid onto the surface of sensing transducer. The proposed sensing chip effectively reduces the volume of the optical interferometer setup that can potentially provide a compact platform for a portable optical instrument.