We studied the influence of the thickness and porosity of the buffer layer on the guiding properties of oxidized porous silicon waveguides (OPSWG). It is demonstrated how a modified anodization process acts on the porosity of the final oxidized porous silicon. In this way, it is possible to control the refractive index jump between the core of OPSWG made of compact silicon dioxide and the bottom buffer layer made of porous silicon dioxide. The adoption of a double-step anodization process decreases the propagation losses to 0.5 dB/cm against the 8 dB/cm measured for the waveguide realized using a single-step anodization. The main reason seems not to be the increase of the difference of refractive index values but the more homogeneous buffer layer obtained along the core of the waveguide. This homogeneous layer permits a better lateral confinement of the light as demonstrated by spatial refractive index profile measurement. (C) 2002 Elsevier Science B.V. All rights reserved.
Buffer layer influence on guiding properties of oxidized porous silicon waveguides / Balucani, Marco; V., Bondarenko; N., Vorozov; Ferrari, Aldo. - In: PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES. - ISSN 1386-9477. - STAMPA. - 16:3-4(2003), pp. 574-579. (Intervento presentato al convegno Spring Meeting of the European-Materials-Research-Society (E-MRS) tenutosi a STRASBOURG, FRANCE nel JUN 18-21, 2002) [10.1016/s1386-9477(02)00649-5].
Buffer layer influence on guiding properties of oxidized porous silicon waveguides
BALUCANI, Marco;FERRARI, Aldo
2003
Abstract
We studied the influence of the thickness and porosity of the buffer layer on the guiding properties of oxidized porous silicon waveguides (OPSWG). It is demonstrated how a modified anodization process acts on the porosity of the final oxidized porous silicon. In this way, it is possible to control the refractive index jump between the core of OPSWG made of compact silicon dioxide and the bottom buffer layer made of porous silicon dioxide. The adoption of a double-step anodization process decreases the propagation losses to 0.5 dB/cm against the 8 dB/cm measured for the waveguide realized using a single-step anodization. The main reason seems not to be the increase of the difference of refractive index values but the more homogeneous buffer layer obtained along the core of the waveguide. This homogeneous layer permits a better lateral confinement of the light as demonstrated by spatial refractive index profile measurement. (C) 2002 Elsevier Science B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.