RESUMO
Topical Editor Catalin Florea shares how to focus the abstract and introduction of a manuscript to convey significance.
RESUMO
It has been experimentally observed that moth-eye antireflective microstructures at the end of As2S3 fibers have an increased laser damage threshold relative to thin-film antireflective coatings. In this work, we computationally study the irradiance enhancement in As2S3 moth-eye antireflective microstructures in order to explain the increased damage threshold. We show that the irradiance enhancement occurs mostly on the air side of the interfaces and is minimal in the As2S3 material. We give a physical explanation for this behavior.
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We investigate the dynamics of photoinduced index changes in chalcogenide As(2)S(3) fibers. Using a novel phase sensitive technique for measuring the photoinduced index change, we find that the index evolution is a two-stage process: it consists of a fast reduction and a subsequent slow increase in the refractive index. We show that the index change depends strongly on the beam intensity with both positive and negative changes possible. These findings can have application in design and fabrication of photoinduced devices such as Bragg gratings and photonic cavities.
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Traumatic hip dislocation might lead to serious complications and a poor outcome. Fortunately, it is a rare condition in pediatric patients. The purpose of this study is to establish and describe the complications caused by hip dislocations associated with transphyseal femoral neck fractures. Therefore, we conducted a literature review that resulted in 11 articles, including 32 patients, older than 10 years of age, suffering from traumatic hip dislocation associated with a transphyseal femoral neck fracture. We presented a case series of three patients with hip fracture-dislocation treated in our clinic that were also evaluated and included in the study. For the 35 patients included in the study group, the percentage of avascular osteonecrosis after hip fracture-dislocation was 88.57%. Traumatic hip dislocation associated with transphyseal femoral neck fracture is a rare condition and has a poor prognosis because of the high incidence of femoral head avascular necrosis (AVN). Reduction should be attempted within six hours the from injury, but this may not minimize the risk of AVN if transphyseal separation occurs. The approach may influence the development of AVN; lateral approach of the hip with great trochanter osteotomy seems to have the lowest number of cases of AVN.
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We demonstrate microstructuring of chalcogenide fiber facets in order to obtain enhanced transmission due to the antireflective properties of the microstructured surfaces. A variety of molding approaches have been investigated for As(2)S(3) and As(3)Se(3) fibers. Transmission as high as 97% per facet was obtained in the case of As(2)S(3) fiber, compared to the native, Fresnel-loss limited, transmission of 83%.
Assuntos
Tecnologia de Fibra Óptica/instrumentação , Fibras Ópticas , Refratometria/instrumentação , Arsênio/química , Desenho de Equipamento , Tecnologia de Fibra Óptica/métodos , Raios Infravermelhos , Selênio/química , Enxofre/químicaRESUMO
We demonstrate microstructuring of chalcogenide fiber end faces in order to obtain enhanced transmission due to the antireflective properties of the microstructured surfaces. A variety of molding approaches have been investigated for As(2)S(3) and As(2)Se(3) fibers. Transmission as high as 97% per facet was obtained in the case of As(2)S(3) fiber, compared to the native, Fresnel-loss limited, transmission of 83%. The potential for hydrophobic character was also demonstrated by increasing the contact angle of water droplets to greater than 120°.
Assuntos
Artefatos , Calcogênios/química , Tecnologia de Fibra Óptica/instrumentação , Lentes , Refratometria/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Vidro/química , Luz , Espalhamento de RadiaçãoRESUMO
Stimulated Brillouin scattering was investigated for the first time in As(2)S(3) single-mode fibers, and also in As(2)Se(3). The propagation loss and numerical aperture of the fibers at 1.56 mum, along with the threshold intensity for the stimulated Brillouin scattering process were measured. From the threshold values we estimate the Brillouin gain coefficient and demonstrate record figure of merit for slow-light based applications in chalcogenide fibers.