Peter Debackere

Bulk sensing experiments using a surface-plasmon interferometer.

Experimental evidence supporting the use of a surface-plasmon interferometer as a biosensor is presented. The device is shown to be capable of bulk refractive index sensing (bulk refractometry) and has a spectral interrogation sensitivity of 315.145 nm/refractive index unit.

Coupling mechanisms for a heterogeneous silicon nanowire platform

We discuss different mechanisms for coupling light from nanophotonic silicon waveguides to different types of materials added on top of these waveguides for enhancing the functionality of these waveguides. We consider diffractive coupling, evanescent coupling, adiabatic coupling and coupling to an overlay and illustrate these with recent experimental and modelling results.

Surface Plasmon Interferometer in Silicon-on-Insulator: Novel Concept for an Integrated Biosensor

We propose a novel configuration for a highly integrated and highly sensitive optical biosensor. The basic element of our sensor is a surface plasmon interferometer consisting of a thin layer of gold embedded in a silicon membrane. We investigate the performance of our sensor by simulation using eigenmode expansion. We calculate that refractive index changes in the order of 10-6 RIU (refractive index unit) are detectable for a component of length 10 mum. Moreover, we illustrate that the operation wavelength of our sensor can be tuned to a desired wavelength for a wide range of environmental refractive indices, making our device suitable for chemo- and biosensing

Employing a 2D surface grating to improve light out coupling of a substrate emitting organic LED

We present simulation and experimental results to achieve increased light extraction of a substrate emitting OLED. We present a comparison between a grating surface on the OLED and an array of microlenses at the interface between substrate and air. This experimentally gives -in both cases- a relative improvement of approx. 30 %. We also demonstrate the concept of a RC2LED, applied to an OLED. The RC2LED is composed by adding a high, low and high index layers between ITO and glass, i.e. the interface between organic layers and glass. These extra layers create a cavity which numerically gives a relative improvement of over 60% at the resonance wavelength of the cavity over a wavelength range of 50-100 nm. The influence of an array of micro lenses in addition to the RC2 layers is also investigated in this paper.

Biosensors in silicon on insulator

We present several nanophotonic biosensors on silicon-on-insulator: ring resonator based devices, slotted ring resonators to increase the interaction between light and the sample, and finally devices based on nanoplasmonic interferometers.

Si based waveguide and surface plasmon sensors

Silicon-on-Insulator (SOI) is a very interesting material system for highly integrated photonic circuits. The high refractive index contrast allows photonic waveguides and waveguide components with submicron dimensions to guide, bend and control light on a very small scale so that various functions can be integrated on a chip. Moreover, SOI offers a flexible platform for integration with surface plasmon based components which in turn allows for even higher levels of miniaturization. Key property of both waveguide types is the mode distribution of the guided modes: a high portion of the light is concentrated outside of the core material, thus making them suitable for sensitive detection of environmental changes. We illustrate chemical and label-free molecular biosensing with SOI microring resonator components. In these microring resonator sensors, the shift of the resonance wavelength is measured. A ring of radius 5 micron is capable of detecting specific biomolecular interaction between the high affinity protein couple avidin/biotin down to a few ng/ml avidin concentration. We describe the integration of surface plasmon waveguides with SOI waveguides and discuss the principle of a highly sensitive and compact surface plasmon interferometric sensor suitable for biosensing. The device is two orders of magnitude smaller than current integrated SPR sensors, and has a highly customizable behavior. We obtain a theoretical limit of detection of 10-6 RIU for a component of length 10 microns. We address material issues and transduction principles for these types of sensors. Besides in chemical sensors, the SOI microring resonators can also be used in physical sensors. We demonstrate a strain sensor in which the shift of the resonance wavelength is caused by mechanical strain. We have experimentally characterized the strain sensors by performing a bending test

Label-free biosensors on silicon-on-insulator optical chips

To come up to the demand for extremely sensitive biosensors for parallel real-time bioanalyses, we present several configurations of label-free biosensors on Silicon-on-Insulator (SOI) optical chips. We discuss results on microring resonators with a non-fouling polymer coating, increased sensitivity with slotted wire resonators and the design and fabrication of an integrated surface plasmon resonance interferometer. The high refractive index contrast of SOI offers submicron-size features with high quality for dense integration, high sensitivity and detection with very low analyte volumes. The fabrication method, 193nm deep-UV lithography, allows for mass production of cheap disposable biochips.

Silicon Nanophotonics and Its Applications in Sensing

We present photonic wire waveguides and basic components in Silicon-on-Insulator (SOI). A large number of these compact SOI devices fit on a single chip. We describe possible applications in biochemical sensing and strain sensing.

Experimental characterization of biosensor based on surface plasmon nano interferometer

Theoretically, label-free biosensing can be achieved by a surface plasmon interferometer in silicon-on-insulator. We present in this paper measurement results validating this theoretical prediction and show this device to be capable of bulk refractive index sensing.