Optical Characterization of Thick Film Bacteriorhodopsin Sensors

Bacteriorhodopsin (BR) is a widely studied photoactive biomolecule with several potential applications in optoelectronics. This work presents a simulation model for thick film BR sensors using the transfer matrix method and Kramers–Kronig analysis to reconstruct the complex refractive index of BR-in-polyvinylalcohol films from extinction spectra. The model is calibrated against spectrophotometer data with two reference configurations. Key structural parameters are estimated through constrained optimization. The results show robust fits and realistic film characteristics. Sensitivity analysis identifies gold electrode thickness, spectral scaling, and BR concentration as dominant factors. The model provides reproducible simulation and enables future structural optimization of BR sensors.