Author
G. Girolami
Bio: G. Girolami is an academic researcher from Agilent Technologies. The author has contributed to research in topics: Photonic crystal & Resonator. The author has an hindex of 3, co-authored 3 publications receiving 673 citations.
Papers
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TL;DR: By measuring the resonant wavelength of a two-dimensional photonic crystal microcavity, a time-resolved sensing capability is demonstrated that can detect the change in refractive index of 0.002.
Abstract: We report an experimental demonstration of an ultracompact biochemical sensor based on a two-dimensional photonic crystal microcavity. The microcavity, fabricated on a silicon-on-insulator substrate, is designed to have a resonant wavelength (λ) near 1.5 µm. The transmission spectrum of the sensor is measured with different ambient refractive indices ranging from n=1.0 to n=1.5. From observation of the shift in resonant wavelength, a change in ambient refractive index of Δn=0.002 is readily apparent. The correspondence between absolute refractive index and resonant wavelength agrees with numerical calculation to within 4% accuracy. The evaporation of water in a 5% glycerol mixture is also used to demonstrate the capability for in situ time-resolved sensing.
454 citations
21 May 2004
TL;DR: By measuring the resonant wavelength of a two-dimensional photonic crystal microcavity, Wang et al. as discussed by the authors detected the change in refractive index of 0.002 using water in 5% glycerol.
Abstract: By measuring the resonant wavelength of a two-dimensional photonic crystal microcavity, we can detect the change in refractive index of 0.002. Evaporative process of water in 5% glycerol is used to demonstrate time-resolved sensing capability
223 citations
TL;DR: In this article, the authors demonstrate ultra-low-loss guiding in bi-periodic photonic crystal waveguides over a large bandwidth of more than 60 nm, and they achieve a propagation loss very similar to that of a dielectric ridge waveguide.
Abstract: For the first time, we experimentally demonstrate ultra-low-loss guiding in bi-periodic photonic crystal waveguides over a large bandwidth of more than 60 nm. In such bi-periodic waveguides, we achieve a propagation loss very similar to that of a dielectric ridge waveguide, which indicates that the dominant loss mechanism in these bi-periodic waveguides is due to fabrication imperfections.
25 citations
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TL;DR: This article reviews the recent progress in optical biosensors that use the label-free detection protocol, in which biomolecules are unlabeled or unmodified, and are detected in their natural forms, and focuses on the optical biosENSors that utilize the refractive index change as the sensing transduction signal.
2,060 citations
TL;DR: Some of the exciting developments so far in miniaturized optofluidic platforms bring fluid and light together and exploit their microscale interaction for a large variety of applications are overviewed.
Abstract: The realization of miniaturized optofluidic platforms offers potential for achieving more functional and more compact devices. Such integrated systems bring fluid and light together and exploit their microscale interaction for a large variety of applications. The high sensitivity of compact microphotonic devices can generate effective microfluidic sensors, with integration capabilities. By turning the technology around, the exploitation of fluid properties holds the promise of highly flexible, tunable or reconfigurable microphotonic devices. We overview some of the exciting developments so far.
946 citations
TL;DR: A rigorous definition for the detection limit of resonant RI sensors is set forth that accounts for all parameters that affect the detection performance and will lead to design strategies for performance improvement of RI sensors.
Abstract: Refractive index (RI) sensors based on optical resonance techniques are receiving a high degree of attention because of the need to develop simple, low-cost, high-throughput detection technologies for a number of applications. While the sensing mechanism of most of the reported RI sensors is similar, the construction is quite different from technique to technique. It is desirable to have a uniform mechanism for comparing the various RI sensing techniques, but to date there exists a degree of variation as to how the sensing performance is quantified. Here we set forth a rigorous definition for the detection limit of resonant RI sensors that accounts for all parameters that affect the detection performance. Our work will enable a standard approach for quantifying and comparing the performance of optical resonance-based RI sensors. Additionally, it will lead to design strategies for performance improvement of RI sensors.
942 citations
TL;DR: The mechanisms by which optofluidics enhances bio/chemical analysis capabilities, including sensing and the precise control of biological micro/nanoparticles, are emphasized.
Abstract: Optofluidics - the synergistic integration of photonics and microfluidics - has recently emerged as a new analytical field that provides a number of unique characteristics for enhanced sensing performance and simplification of microsystems. In this review, we describe various optofluidic architectures developed in the past five years, emphasize the mechanisms by which optofluidics enhances bio/chemical analysis capabilities, including sensing and the precise control of biological micro/nanoparticles, and envision new research directions to which optofluidics leads.
797 citations
TL;DR: A platform for real-time binding assays on sensor arrays based on silicon ring resonators is presented in this article, where an array of 32 sensors is interrogated simultaneously and 24 simultaneous binding curves are produced.
Abstract: A platform for performing rapid, real-time binding assays on sensor arrays based on silicon ring resonators is presented in this paper. An array of 32 sensors is interrogated simultaneously. Using eight sensors as controls, 24 simultaneous binding curves are produced. The bulk refractive index sensitivity of the system was demonstrated down to 7.6 × 10-7 and sensor-to-sensor variability is 3.9%. Using an 8-min incubation, real-time binding was observed over 8-logs of concentration down to 60 fM using immobilized biotin to capture streptavidin diluted in bovine serum albumin solution. Multiplexing in complex media is demonstrated with two DNA oligonucleotide probes. Time to result and repeatability are demonstrated to be adequate for clinical applications.
553 citations