Experimental analysis and modeling of the penetration depth of uniform and apodized integrated Bragg reflectors

Our proposed method quantifies the penetration depth of integrated Bragg gratings that form on-chip Fabry-Pérot cavities. Through the characterization of the integrated cavities, we evaluate the wavelength-dependent penetration depth by studying its impact on the free spectral range and comparing it with theoretical models, for both uniform and apodized gratings. The analysis of the results is relevant for those who model, fabricate and characterize Bragg reflectors as effective mirrors when the length of the order of the wavelength is needed.