Refractometric sensitivity of Bloch surface waves: perturbation theory calculation and experimental validation

Area of Science:

• Photonics
• Nanotechnology
• Sensor Technology

Background:

• Bloch surface waves (BSWs) are electromagnetic waves confined to a one-dimensional photonic crystal interface.
• Kretschmann's configuration is a common method for exciting surface waves.
• Sensitivity to external refractive index changes is crucial for BSW sensor applications.

Purpose of the Study:

• To analytically calculate the sensitivity of one-dimensional BSW sensors to refractive index variations.
• To validate the analytical approach using numerical simulations and experimental data.
• To provide insights into photonic crystal design for enhanced BSW sensing performance.

Main Methods:

• First-order perturbation theory was employed for analytical calculations of BSW sensor sensitivity.
• Transfer matrix method (TMM) simulations were used for validation.
• Experimental measurements were conducted on a specific photonic crystal structure.

Main Results:

• Analytical calculations were validated against TMM simulations and experimental results.
• Experimental sensitivities for TE and TM modes were (8.4±0.2)×10^2 and (8.4±0.4)×10^2 nm/RIU, respectively.
• The perturbation theory approach showed low errors (0.02% for TE, 4% for TM) compared to experimental data.

Conclusions:

• First-order perturbation theory accurately predicts BSW sensor sensitivity.
• The study offers valuable insights for optimizing photonic crystal structures in BSW sensor design.
• Accurate sensitivity analysis is key for developing high-performance BSW-based sensors.