ABSTRACT
A new method for confining and guiding two-dimensional (2D) optical waves is proposed using low-refractive-index materials as cores of metal-gap waveguides. A proper choice of the refractive index of claddings prohibits 2D optical waves from propagating inside the claddings, resulting in strong confinement of waves inside the low-refractive-index cores. We numerically demonstrate that this new method for guiding 2D optical waves can achieve stronger confinement than the conventional one using high-refractive-index cores. This strong confinement leads to efficient guiding of 2D optical waves not only at straight path, but also at sharp 90 degrees bends with negligible radiation losses.
ABSTRACT
A conventional method to synthesize diffractive optical elements and computer-generated holograms (CGH's) with high diffraction efficiency relies on an increase of phase levels. To fabricate such a device, one should perform electron-beam (e-beam) lithography with multiple-dose exposures or multiple-step photolithography. Here we describe a one-step method, which is based on the effective medium theory, for the fabrication of a multilevel phase CGH. The phase modulations required in cells of a CGH are constructed by means of dividing these cells into fine (subwavelength) structures. The surface features of these fine structures control their corresponding indices, and their values can be calculated according to the effective medium theory. By proper selection of the fine structures, based on the requirements of the phase modulation of the cells, a CGH with multilevel phases is synthesized when a binary structure is relieved on the dielectric material. Then the CGH can be fabricated by direct e-beam lithography or one-step photolithography through an amplitude mask followed by an ion-etching treatment. The experimental results showed that the reconstructed wave field is in good agreement with that simulated by a computer, indicating the effectiveness of the proposed method.
Subject(s)
Blinking , Blood Pressure , Heart Rate , Skin Temperature , Tobacco Smoke Pollution , Adult , Carbon Dioxide/analysis , Carbon Monoxide/analysis , Female , Humans , Male , Microclimate , Nitrogen Dioxide/analysis , Nitrous Oxide/analysis , Respiration , SmokingABSTRACT
For the purpose of measuring concentrations of gentamicin (GM) into body fluids (pancreatic juice, abdominal cavity, and bile) after intramuscular injection, the authors conducted experiments using adult mongrel dogs with following results. 1) The highest concentration in pancreatic juice was observed 1 approximately 1.5 hours after single intramuscular administration of 4 mg/kg. The highest concentration was 51.3% of that in blood. 2) The highest concentration in bile was observed 30 minutes approximately 1 hour after single intramuscular administration of GM. The concentration was about 50% of that in blood. 3) The diffusion of GM into the abdominal cavity was good after single intramuscular administration. 4) The rate of urinary excretion was high as is generally known.
