Highly Sensitive, Bloch Surface Wave D-Type Fiber Sensor

A novel sensor based on a D-type optical fiber coated with a specially designed dielectric multilayer forming a one-dimensional photonic bandgap structure is proposed. The characteristics of its propagation modes are numerically analyzed at a wavelength of 785 nm to evaluate the sensor’s performance. The results show that its sensitivity can drastically exceed that of its metal-coated, surface plasmon resonance counterpart, due to the sharp resonance and low wave-propagation loss of its Bloch surface wave. The novel sensor can also be easily adapted for all kinds of aqueous analytes of different refractive indices by modifying the photonic bandgap structure. This could lead to the development of compact, ultra-sensitive biochemical sensing devices.