In this paper, we present the modeling and design of a new approach to a miniaturized electric field sensor, based on a whispering-gallery-mode resonator coupled with a Fabry-Perot cavity in ...silicon-on-insulator technology. The sensing element consists of a metal oxide semiconductor capacitor, optimized to achieve high electrical sensitivity and low optical losses. The theoretical model of the whole sensor architecture includes the influence of all electrical and optical parameters, including thin oxide thickness, silicon and polysilicon doping concentration, optical losses due to propagation, absorption and scattering, wavelength and amplitude characteristics of the architecture, charge accumulation effects in the capacitor, and thermal effects. The very high sensitivity of this device, demonstrated by simulations, is due to the simultaneous influence of the two coupled resonators and the metal oxide semiconductor structure.
In this paper, we report, for the first time to the best of our knowledge, the detailed modeling and design of a guided-wave optical angular-velocity sensor based on Raman amplification in a ...silicon-on-insulator resonant cavity. Theoretical results for continuous-wave Raman laser emission are compared with experiments in the literature, demonstrating very good agreement. The model includes the influence of a number of physical effects on the propagation of both counterpropagating pumps and Stokes waves, such as stimulated Raman scattering, two- photon absorption, free-carrier dispersion, self- and cross-phase- modulation induced by the Kerr effect, and the lock-in effect. Investigation of optical dithering features by intracavity phase modulation is also presented. Performance is derived to optimize the device sensitivity for both medical, robotics, automotive, and entertainment gyro applications.
Electromagnetic field photonic sensors Passaro, V.M.N.; Dell’Olio, F.; De Leonardis, F.
Progress in quantum electronics,
2006, 2006-1-00, Volume:
30, Issue:
2
Journal Article
Peer reviewed
In this paper, we review the different configurations proposed for electromagnetic field optical sensing. Intrinsic and extrinsic optical fiber sensors for electric and magnetic field measurement are ...examined, including those realized jacketing the fiber by magnetostrictive, conductive, electrochromic and polymeric materials and those measuring induced strain by magnetostrictive, electrostrictive and piezoelectric transducers. Extrinsic optical fiber sensors exploiting magneto-optic, electro-optic and Joule effects are also presented.
Moreover, integrated optical electric and magnetic field sensors in which microwave signal provided by an antenna modulates the optical signal generated by an optical source are reviewed. Finally, active and coupled resonators based on electric field sensors are investigated.
Nonlinear optical signal processing by ultrafast Raman pulses in silicon-on-insulator rib waveguides is theoretically investigated in this paper. Stimulated Raman scattering, two-photon absorption, ...free carrier dispersion, self- and cross-phase-modulation-induced by Kerr effect, walk-off, group velocity dispersion, pump depletion, self-steeping, and polarization coupling are taken into account by a very general modeling under subpicosecond regime. Raman amplification, multiwavelength conversion, soliton formation, and pulse compression are presented and discussed. Finally, some simulations for generation of higher order Stokes pulses in mid-IR region are given.
The management of neuropsychiatric systemic lupus erythematosus (NPSLE) still remains empirical and based on clinical experience due to the lack of randomized controlled trials.
To report the ...experience accumulated in a single tertiary referral centre about treatment of severe cases of NPSLE patients and to discuss therapeutic strategies on the background of EULAR recommendations.
Retrospective analysis of all consecutive cases of severe NPSLE treated in our centre since 1990 to 2010, satisfying the 1999 ACR criteria.
Among 633 SLE patients who consecutively attended our centre, 231 (36%) displayed at least one neuropsychiatric (NP) manifestation for a total of 408 events attributable to SLE. Thirty-one patients (4.8%), 27 females and 4 males, experienced 35 major NP events requiring immunosuppressive therapy (including 3 relapses and 1 new event). An aggressive immunosuppressive strategy was applied to those patients with an immune mediated inflammatory NP event and to those patients with an increased disease activity as judged by ECLAM and SLEDAI scores. Overall at the end of the therapy 74% of the patients reached clinical remission or significant improvement of their symptoms measured by mean SLEDAI (from 10.09 ± 1.09 to 2.04 ± 0.52, P<0.0001) and ECLAM (from 4 ± 0.34 to 1.38 ± 0.37, P<0.001) scores.
The prevalence of NP involvement, described in our case series, is similar to those reported in literature as well as the treatment strategies applied. Nowadays, it is not possible to establish a standardized approach for each single NPSLE manifestation, and different therapeutic strategies must be tailored taking into account the most probable pathogenic mechanism involved, the general disease activity background, the co-morbidities, the type and the stage of the systemic involvement.
In this paper, the detailed modeling of Raman lasers in silicon-on-insulator guided-wave racetrack resonant microcavities is developed. Modeling based on full-vectorial equations and systematic ...design rules are presented for the first time. Simulation results are compared with experimental and theoretical results in literature, demonstrating a very good agreement. Moreover, parametric investigations including waveguide sizes, pump and Stokes coupling factors, cavity shape, polarization states, and waveguide orientation are presented, and their influence on the laser features are discussed.
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