Random porous silicon multilayers: application to distributed Bragg reflectors and interferential Fabry - Pérot filters

Random porous silicon dielectric multilayers are proposed as interesting materials for applications as optical components. Distributed Bragg reflectors and interferential Fabry - Perot filters are demonstrated. The randomness is obtained as a variation in the layer thicknesses. The advantage in the use of random instead of periodic multilayers lies in the obtention of a wider stop-band in Bragg reflectors with the same difference in the refractive indexes of the layers and in a higher finesse in Fabry - Perot filters.