Fabry-Perot-based surface plasmon resonance sensors

A new sensing approach based on the use of an optical Fabry-Pérot (FP) cavity in conjunction with surface plasmon resonance (SPR) is proposed and theoretically investigated. The impact of the SPR on the intensity and phase response of the proposed sensor structure is evaluated using a modified FP model that takes into account the SPR effect. Compared to the conventional optical-phase-detection-based Kretschmann configuration, the proposed sensing approach requires only the measurement of the output power spectrum over a narrow wavelength span of several nanometers to evaluate the phase responses of the sensor, making it more attractive for practical high-sensitivity sensing applications

Theory, figures of merit, and design recipe of the plasmonic structure composed of a nano-slit aperture surrounded by surface corrugations

We theoretically investigate a widely-used plasmonic structure composed of a nano-slit aperture surrounded by surface corrugations. A systematical semi-analytical theory in form of two nested coupled-mode models is developed to provide intuitive physical pictures. Based on the theory, figures of merit (FoMs) of the structures designed for normal and for oblique incidence/beaming are defined for the first time to incorporate the interlinks among key structural parameters, making global optimization simple and efficient. Both the theory and the FoMs are quantitatively validated with exhaustive calculations and shown to be highly accurate on performance prediction and structural optimization. With the theory and the FoMs, an efficient, effective and standard recipe is introduced for optimal structure design. We believe this work will help to understand the mechanisms of and to facilitate the design of such a structure in various configurations used in various applications

Unidirectional coupling of surface plasmons with ultra-broadband and wide-angle efficiency: potential applications in sensing

A cascaded-grating coupling scheme for unidirectionally coupling and launching surface plasmons from free-space light with ultra-broadband and wide-angle efficiency is proposed and theoretically investigated, and the potential applications in sensing are discussed. The cascaded sub-gratings of different periods couple the incident light over a relatively wide wavelength and angular range into surface plasmon polaritons (SPPs). After traveling a short distance, the SPPs interact with the sensed medium, and then are coupled back into freely propagating light through the nanoslit in the metal film. By observing the changes of SPP-mediated light coupled out through the slit, broadband sensing is achieved. A quantitative theoretical model is developed for performance prediction and validated with aperiodic Fourier modal method. Proof-of-principle demonstrations show that the spectral full-width-half-maximum reaches 400 nm and meanwhile the angular width is up to 25°, both of which are almost four times compared to the reference single-periodic gratings. A wavelength sensitivity as high as 852 nm RIU-1 (RIU, refractive index units) and a relative intensity change up to ∼5 × 104% RIU-1 are obtained

Theory of the scattering of light and surface plasmon polaritons by finite-size subwavelength metallic defects via field decomposition

A theoretical model is presented for the scattering of light and surface plasmon polaritons (SPPs) by finite-size subwavelength metallic defects. Based on the decomposition of the scattered fields into SPPs and quasi-cylindrical waves (CWs), an SPP–CW model is developed to depict the multiple scattering of SPPs and CWs in finite-size defects using the elementary scattering processes in a single one. The involved elementary scattering of the CW, as well as the CW-related coefficients, which are difficult or even impossible to define and calculate according to classical scattering theory, is clarified. A close relationship between the scattering coefficients of the SPP and those of the CW has been pointed out and used to simplify the developed model. Compared to the corresponding pure SPP model and the fully vectorial computational data, the SPP–CW model is shown to be versatile and quantitatively accurate for finite-size defects such as grooves, ridges, slits or even hybrid systems of various geometrical parameters, over a broad spectral range from the visible to the thermal infrared regime

Down-regulation of Stargazin Inhibits the Enhanced Surface Delivery of α-Amino-3-hydroxy-5-methyl-4-isoxazole Propionate Receptor GluR1 Subunit in Rat Dorsal Horn and Ameliorates Postoperative Pain

Stargazin is the first transmembrane protein known to regulate synaptic targeting of α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors. Yet, it is unclear whether regulation of the surface delivery of spinal AMPA receptor subunits by stargazin contributes to postoperative pain development

OBS based transparent optical networking policy (Invited)

As optically random access memory is not commercially available, and with the fiber being cheaper and cheaper, the core fiber bandwidth utilization is not the key factor of the network, how to use the huge bandwidth flexibly and efficiently is one of the hot topics of optical networks. Optical burst switching (OBS) is thought to be the best way to adapt the bursty traffic, and can be statistically using the optical resources, so that OBS based transparent optical network attracting more and more attentions. However, the precondition of most of the OBS networking solution is based on wavelength conversion, which is limited by the nonlinear of materials. We proposed a novel networking policy by using dual fiber links server model along with traffic spacing mechanism (TSM) by address differentiation, the transmitting IP directly in optical domain for traffic data between physically adjacent nodes, with no necessary burst assembling (NABAN). The theoretical results show that this method can improve network performance and be practically used in fields.EI

Optical all-pass filters designing for dispersion compensation in high-speed WDM optical communication systems

A new configuration of tunable chromatic dispersion compensator based on optical all-pass filter utilizing MZIs and ring resonators is described. A two-stage device is demonstrated with FSR of 100GHz, tuning range of ??100ps/nm and a group delay ripple less than 2.3ps. ?2006 OSIA.EI

Start Wavelength Assignment Policy - A Wavelength Contention Resolution for Optical Burst Switching Networks

Most studies of optical burst switching (OBS) networks are under a fundamental assumption that full wavelength conversion is available throughout the network. In practice, however economic and technical considerations are likely to dictate a more limited and sparse deployment of wavelength converters in the optical network. Therefore, we present a new start wavelength assignment policy for the absence of (full) wavelength conversion capabilities in the OBS Networks. The performance study indicates that, our new scheme is robust under wavelength continuity constraint as well as Poisson and Self-Similar Traffic.Engineering, Electrical & ElectronicTelecommunicationsEICPCI-S(ISTP)

A Novel Architecture for Metropolitan Area Networks

A novel architecture, dual-fiber-link optical burst switching which has the similar functions of fiber-delay-lines, partial wavelength-converter, and deflection-routing, is proposed for MAN. Results show that it can exponentially decrease burst blocking probability. ? 2008 Optical Society of America.EI