Optimizing loss of the dielectric stack for Bloch-surface-wave sensors under different interrogation schemes

For enhancing the sensitivity of the Bloch surface wave-based sensing applications, the dependency of the Bloch surface wave (BSW) resonance dip and the associated phase change on the loss of a truncated one-dimensional photonic crystal structure is numerically analyzed and studied. Furthermore, through evaluating the sensitivity of a BSW sensor based on the intensity interrogation scheme and the phase detection method, a comparison is carried out to optimize the sensing performance. The results demonstrate that the sensing sensitivity of the BSW sensor is significantly affected by the applied sensing schemes. It is shown that the optimized device loss is not the same for different sensing schemes. Relatively high phase-detection sensing sensitivity can be maintained for low-loss BSW devices, while that of the intensity interrogation scheme may drop sharply. On the other hand, the performance of intensity interrogation scheme is less affected by the higher device loss. Our result could be useful for improving the performance of the BSW sensors and selecting the appropriate sensing scheme for such devices.