Effect of different stacking orders of Ta2O5 and SiO2 films on the reflective properties of a blue distributed Bragg reflector

Abstract

The Ta2O5 and SiO2 single-layer films were deposited on the glass substrates to measure their refractive properties under different optical wavelengths. After that, the Ta2O5 and SiO2 films were used as high and low refractive index materials to design the blue distributed Bragg reflectors (DBRs) with different periods. The approximate formula proposed by Sheppard was used to calculate the maximum reflectance ratio of the bi-layer SiO–Ta2O5 DBRs with two, four, six, and eight periods. The COMSOL Multiphysics software was used to simulate the reflective spectra of the SiO2–Ta2O5 DBRs with different stacking orders and periods by incorporating the refractive indexes of the Ta2O5 and SiO2 films at a wavelength of 550 nm. The SiO2–Ta2O5 DBRs with different periods were fabricated by depositing the Ta2O5 and SiO2 films on glass substrates, and their reflective properties were measured. We compared the measured reflective spectra of the fabricated SiO2–Ta2O5 DBRs with the simulated reflective spectra to show the effect of the different stacking orders.