Bragg reflector formed on oxidised porous silicon

The manufacturing of a porous silicon Bragg reflector on P⁺ silicon substrate is investigated and the effects of oxidation on the Bragg reflector parameters is studied, notably the shift of the central wavelength after oxidation. This Letter shows how to anticipate the changes due to oxidation rather than to endure them. First, the variations in the refractive index and thickness after oxidation were studied. Then, from these measurements, an oxidised porous silicon Bragg reflector centred at 1550 nm was formed by anticipating the shift of central wavelength during oxidation. There was a good correlation between the experimental and theoretical spectra of the Bragg reflector.