OPTICAL RESPONSE OF PORUS SILICON AND POROUS ALUMINA HYBRID STRUCTURES

LUISA CENCHA; LUISINA FORZANI; RAUL URTEAGA; ROBERTO KOROPECKI

Tarragona

Congreso; International Bianual Conference on Porous Semiconductors and Technology; 2016

In thiswork are proposed hybrids structures builtwith porous alumina (AAO) cavities and side distributed Bragg reflectors (DBRs)made of porous silicon (PSi).We build hybridmicrocavitieswith a central defectof porous aluminawhich is placed between two porous silicon distributed Bragg reflectors. In thisway we construct a Fabry-Perot resonatorwith high reflectivity and lowabsorption that improves the finesse ofthe filter respect to amicrocavity constructed onlywith porous silicon.We evaluate theoretically and experimentally the optical response of this structures. The combination of these two porousmaterials can be used to exploit the distinguishing features of eachmaterial. The Qfactor of such devices (ameasure of the sharpness of the characteristics of the spectrum) is compared using numerical simulationswith that ofmicrocavities entirelymade of PSi.We also explore a simpler design inwhich one of the Bragg reflectors is replaced by the aluminumthat remains bound to the alumina after its fabrication. We theoretically explore the potential of the proposaland its limitationswhen considering a possible roughness of the layers. The role of surface roughness is taken into account and experimental results on freestandingmicrocavities are presented.