The use of photonic integrated circuits made of polymer materials represents a solution for obtaining low-cost immunosensors for fast clinical diagnosis. In this paper are presented the simulation studies of a photonic integrated sensor on silicon substrate based on the configuration of Young interferometer. The core and cladding materials of the photonic sensor are polymeric materials. This sensor works for the detection of the surrounding medium refractive index variation and also for the detection of a thin adsorbed layer on the sensor surface. Simulations are performed using the Beam Propagation Method and 2D mode solvers for obtaining the relation between the variation of the surrounding refractive index or the presence of an adsorbed layer and the displacement of the interference fringe position. From this dependence one can calculate the sensor sensitivity and also one can estimate the detection limit. In order to obtain reliable results it is necessary to have waveguides which presents single mode operation regime both on the horizontal and vertical direction. Rib waveguides which are more prone for satisfying single mode condition were considered. The suppression of the higher order modes on the vertical direction by leakage in the silicon substrate is made by adjusting the thickness of the silicon dioxide buffer layer.

Date Published: 10 May 2012
PDF: 6 pages
Proc. SPIE 8431, Silicon Photonics and Photonic Integrated Circuits III, 84311V (10 May 2012); doi: 10.1117/12.922993

Published in SPIE Proceedings Vol. 8431:
Silicon Photonics and Photonic Integrated Circuits III
Laurent Vivien; Seppo K. Honkanen; Lorenzo Pavesi; Stefano Pelli, Editor(s)