RESUMO
We demonstrate a direct, single measurement technique for characterizing the dispersion of a photonic crystal waveguide (PCWG) using a tapered fiber evanescent coupling method. A highly curved fiber taper is used to probe the Fabry-Pérot spectrum of a closed PCWG over a broad k-space range, and from this measurement the dispersive properties of the waveguide can be found. Waveguide propagation losses can also be estimated from measurements of closed waveguides with different lengths. The validity of this method is demonstrated by comparing the results obtained on a 'W1' PCWG in chalcogenide glass with numerical simulation.
Assuntos
Algoritmos , Análise de Falha de Equipamento/instrumentação , Análise de Falha de Equipamento/métodos , Tecnologia de Fibra Óptica/instrumentação , Desenho de EquipamentoRESUMO
We present experimental results on post-tuning the dispersion of a two-dimensional photonic crystal waveguide made from Ge(33)As(12)Se(55) chalcogenide glass by exploiting the material photosensitivity to near-bandgap light. The change in the refractive index and volume of the material in response to exposure to 633nm light resulted in a shift of more than 5nm in the resonant coupling wavelength between a tapered optical fiber and the modes of a W1 waveguide. This represents a first proof of principle demonstration of the photosensitive post-tuning of a planar photonic crystal device.
RESUMO
We demonstrate highly efficient evanescent coupling between a highly nonlinear chalcogenide glass two dimensional photonic crystal waveguide and a silica fiber nanowire. We achieve 98% insertion efficiency to the fundamental photonic crystal waveguide mode with a 3dB coupling bandwidth of 12nm, in good agreement with theory. This scheme provides a promising platform to realize low power nanocavity based all-optical switching and logic functions.
RESUMO
We demonstrate resonant guiding in a chalcogenide glass photonic crystal membrane. We observe strong resonances in the optical transmission spectra at normal incidence, associated with Fano coupling between free space and guided modes. We obtain good agreement with modeling results based on three-dimensional finite-difference time-domain simulations, and identify the guided modes near the centre of the first Brillouin zone responsible for the main spectral features.
RESUMO
External content sources such as MEDLINE(®), National Institutes of Health (NIH) grants and conference websites provide access to the latest breaking biomedical information, which can inform pharmaceutical and biotechnology company pipeline decisions. The value of the sites for industry, however, is limited by the use of the public internet, the limited synonyms, the rarity of batch searching capability and the disconnected nature of the sites. Fortunately, many sites now offer their content for download and we have developed an automated internal workflow that uses text mining and tailored ontologies for programmatic search and knowledge extraction. We believe such an efficient and secure approach provides a competitive advantage to companies needing access to the latest information for a range of use cases and complements manually curated commercial sources.
Assuntos
Mineração de Dados , Descoberta de Drogas , Processamento de Linguagem Natural , Sistemas de InformaçãoRESUMO
Free-standing "AMTIR-1" (Ge33As12Se55) chalcogenide glass films have been patterned using a focused ion beam (FIB) to create two-dimensional photonic crystal membranes. The triangular lattices were selected for a photonic bandgap relevant to fiber telecommunications. Optical measurements of transmission spectra as a function of incident angle showed clear signs of Fano resonances, indicating that the structures had strongly modified guided modes.
RESUMO
STUDY OBJECTIVES: To investigate prescribing patterns for antipsychotic regimens based on intramuscular haloperidol or intramuscular olanzapine for treating acute agitation; to compare the costs of each drug regimen, which included adjunctive anxiolytics and/or anticholinergics; and to compare the effectiveness and safety of each drug regimen. DESIGN: Retrospective medical record review. SETTING: State psychiatric facility. PATIENTS: Twenty-seven patients who received intramuscular haloperidol to treat 47 episodes of acute agitation and 26 patients who received intramuscular olanzapine to treat 38 episodes. MEASUREMENTS AND MAIN RESULTS: Data from patients receiving the antipsychotic regimens between August 2004 and March 2007 were reviewed. Mean +/- SD doses were 6.4 +/- 2.4 mg (range 2.5-10 mg) for haloperidol and 8.1 +/- 2.3 mg (range 5-10 mg) for olanzapine. The mean +/- SD cost of treating an episode of agitation with haloperidol was significantly lower at $4.06 +/- 3.98 (range $1.74-18.35) versus $27.84 +/- 10.40 (range $21.58-52.46) for olanzapine (p<0.0001). Significantly fewer patients who received haloperidol than patients who received olanzapine required additional pharmacotherapy to manage agitation (41% vs 69%, chi(2)=4.34, p=0.04). No significant differences were found between groups in the mean number of repeat doses of psychotropic drugs needed/episode (0.6 [range 0-5] for haloperidol vs 0.8 [range 0-3] for olanzapine, p=0.47), in the percentages of patients who required seclusion and/or restraints (59% for haloperidol vs 58% for olanzapine, chi(2)=0.01, p=0.91), or in time spent in seclusion and/or restraints (3.7 +/- 7.1 for haloperidol vs 3.6 +/- 6.5 hrs for olanzapine, p=0.92). No adverse events were documented with either drug. CONCLUSION: For the treatment of acute episodes of agitation, regimens based on intramuscular haloperidol were significantly less expensive than and at least as effective as those based on intramuscular olanzapine.