Berlin 2008 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 17: Poster I

HL 17.21: Poster

Monday, February 25, 2008, 16:30–19:00, Poster D

Development of Photonic Sensors for Parallel Molecule Detection Based on Microresonators — •Mario Hauser, Christian Sailer, Cristian Gohn, Christian Schäfer, Wolfgang Löffler, and Heinz Kalt — Universität Karlsruhe (TH), Karlsruhe, Germany

We report on the development of versatile photonic sensors for label-free detection of proteins and DNA on the basis of semiconductor microdisks.

The detection principle bases on the shift of the frequency of optical whispering gallery modes (WGMs) and has been proven in the case of silica spheres [1]. Each resonator will be functionalized by fixing proteins to its perimeter which can selectivley bind to well defined partners as in the case for complementary DNA sequences or antigen/antibody combinations. The evanescent field of the WGM polarizes a molecule attached to the resonator which in return shifts the mode frequency.

For detection of the modal shift of WGMs an add/drop filter scheme with integrated waveguides passing a series of microdisks at a small distance is shown. Waveguides and microdisks can be etched simultaneously with standard semiconductor technologies from a single substrate to form an integrated device. We present first results of the fabrication and the characterization of the optical resonances.

[1] S. Arnold et. al., Shift of whispering-gallery modes in microspheres by protein adsorption, Optics Lett., vol. 28, 272 (2003)