We present the design, fabrication, and characterisation of an array of optical slot-waveguide ring resonator sensors, integrated with microfluidic sample handling in a compact cartridge, for multiplexed real-time label-free biosensing. Multiplexing not only enables high throughput, but also provides reference channels for drift compensation and control experiments. Our use of alignment tolerant surface gratings to couple light into the optical chip enables quick replacement of cartridges in the read-out instrument. Furthermore, our novel use of a dual surface-energy adhesive film to bond a hard plastic shell directly to the PDMS microfluidic network allows for fast and leak-tight assembly of compact cartridges with tightly spaced fluidic interconnects. The high sensitivity of the slot-waveguide resonators, combined with on-chip referencing and physical modelling, yields a volume refractive index detection limit of 5 x 10(-6) refractive index units (RIUs) and a surface mass density detection limit of 0.9 pg mm(-2), to our knowledge the best reported values for integrated planar ring resonators.

QC 20100715

We present an experimental study of an integrated slot-waveguide refractive index sensor array fabricated in silicon nitride on silica. We study the temperature dependence of the slot-waveguide ring resonator sensors and find that they show a low temperature dependence of -16.6 pm/K, while at the same time a large refractive index sensitivity of 240 nm per refractive index unit. Furthermore, by using on-chip temperature referencing, a differential temperature sensitivity of only 0.3 pm/K is obtained, without individual sensor calibration. This low value indicates good sensor-to-sensor repeatability, thus enabling use in highly parallel chemical assays. We demonstrate refractive index measurements during temperature drift and show a detection limit of 8.8 x 10-6 refractive index units in a 7 K temperature operating window, without external temperature control. Finally, we suggest the possibility of athermal slot-waveguide sensor design.

Carrier illumination is an optical, fast, and nondestructive technique for an ultrashallow complementary metal oxide semiconductor structure characterization based on the measurement of differential probe laser reflectivity changes, which originate from refractive index variations induced by excess carriers generated by a second modulated pump laser. By changing the pump laser power it is possible to influence the depth of the main internal reflection and thus to sense the shape of the underlying electrically active profile. The extraction of the latter is, however, critically dependent on our in-depth physical understanding of the underlying processes. In this work, recent progress will be discussed with respect to the improved physical modeling of the generation-recombination processes (SRH, Auger, indirect phonon absorption, and free carrier absorption), mobilities, impact of temperature (heating by the lasers), and influence of slow surface state traps (time dependent behavior). In order to quantify the contribution of each parameter in the power curves (representing the probe reflectivity signal versus the pump power), three-dimensional axisymmetric numerical device simulations have been performed. These simulations will be compared to experimental data for a variety of structures (bulk material and chemical vapor deposition grown layers).

We report on dye-based photonic sensing systems that are fabricated and packaged at waferscale. The realized dye-based photonic sensors include an environmental NO2 sensor and a sunlight ultraviolet light (UV) A+B sensor. For the first time luminescent organic nanocomposite thin-films

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