In this paper, a vector ray-tracing model (VRT) is used to simulate the optical caustic structures associated with the secondary rainbow for an ellipsoidal droplet illuminated by a Gaussian beam. The optical caustics ...In this paper, a vector ray-tracing model (VRT) is used to simulate the optical caustic structures associated with the secondary rainbow for an ellipsoidal droplet illuminated by a Gaussian beam. The optical caustics of drops with an equatorial radius a = 50 μm, 100 μm, 200 μm, and 500 μm are studied at the same drop/beam ratios (i.e. γ the ratio between the droplet equatorial radius and the Gaussian beam waist) using concentric illumination with a Gaussian beam, and the effect of droplet size on the optical caustics is analyzed. The curvature of the rainbow fringe and the evolution of the cusp caustics position, in this case, are obtained;the diameter range of droplet shape (ellipsoid) measured by Gaussian beam illumination is broadened. Based on this model, the effects of the relative positions d = 0, 0.5y<sub>R</sub>, and y<sub>R</sub> on the optical caustics of the droplet when the center of the Gaussian beam deviates from the droplet center (the center of the Gaussian beam waist is on the same y-axis as the droplet center) are discussed. The optical caustics of the droplet when the center of the Gaussian beam is off the droplet center (the center of the Gaussian beam waist is on the z-axis with the droplet center) are also discussed. The effects of the relative positions of the center of the beam waist and the droplet center d = 0, 0.5y<sub>R</sub>, and y<sub>R</sub> on the optical caustics are also discussed. A method of measuring droplet shape with Gaussian beam illumination is proposed when the beam waist center is coaxial with the droplet center.展开更多
Driven by their potential applications, vectorial optical fields with spatially inhomogeneous states of polarization within the cross section have drawn significant attention recently. This work intends to review some...Driven by their potential applications, vectorial optical fields with spatially inhomogeneous states of polarization within the cross section have drawn significant attention recently. This work intends to review some of the latest development of this rapidly growing field of optics and offer a general overview of the current status of this field in a few areas. Mathematical descriptions of generalized vectorial optical fields are provided along with several special examples. A time-reversal methodology for the creation of a wide variety of exotic optical focal fields with prescribed characteristics within the focal volume is presented. Recently developed methods for the generation of vectorial optical fields that utilize fiber lasers,digital lasers, vectorial optical field generator, metasurfaces or photoalignment liquid crystals are summarized. The interactions of these vectorial optical fields with various micro-and nano-structures are presented and the prospects of their potential applications are discussed. The connection of vectorial optical fields with higher dimensionality in quantum information is summarized.展开更多
文摘In this paper, a vector ray-tracing model (VRT) is used to simulate the optical caustic structures associated with the secondary rainbow for an ellipsoidal droplet illuminated by a Gaussian beam. The optical caustics of drops with an equatorial radius a = 50 μm, 100 μm, 200 μm, and 500 μm are studied at the same drop/beam ratios (i.e. γ the ratio between the droplet equatorial radius and the Gaussian beam waist) using concentric illumination with a Gaussian beam, and the effect of droplet size on the optical caustics is analyzed. The curvature of the rainbow fringe and the evolution of the cusp caustics position, in this case, are obtained;the diameter range of droplet shape (ellipsoid) measured by Gaussian beam illumination is broadened. Based on this model, the effects of the relative positions d = 0, 0.5y<sub>R</sub>, and y<sub>R</sub> on the optical caustics of the droplet when the center of the Gaussian beam deviates from the droplet center (the center of the Gaussian beam waist is on the same y-axis as the droplet center) are discussed. The optical caustics of the droplet when the center of the Gaussian beam is off the droplet center (the center of the Gaussian beam waist is on the z-axis with the droplet center) are also discussed. The effects of the relative positions of the center of the beam waist and the droplet center d = 0, 0.5y<sub>R</sub>, and y<sub>R</sub> on the optical caustics are also discussed. A method of measuring droplet shape with Gaussian beam illumination is proposed when the beam waist center is coaxial with the droplet center.
基金support provided through the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learningalso partially supported by the National Natural Science Foundation of China(91438108 and 61505062)the Chinese Scholarship Council for supporting their study at the University of Dayton through the Joint Training PhD Program and Visiting Scholar Program
文摘Driven by their potential applications, vectorial optical fields with spatially inhomogeneous states of polarization within the cross section have drawn significant attention recently. This work intends to review some of the latest development of this rapidly growing field of optics and offer a general overview of the current status of this field in a few areas. Mathematical descriptions of generalized vectorial optical fields are provided along with several special examples. A time-reversal methodology for the creation of a wide variety of exotic optical focal fields with prescribed characteristics within the focal volume is presented. Recently developed methods for the generation of vectorial optical fields that utilize fiber lasers,digital lasers, vectorial optical field generator, metasurfaces or photoalignment liquid crystals are summarized. The interactions of these vectorial optical fields with various micro-and nano-structures are presented and the prospects of their potential applications are discussed. The connection of vectorial optical fields with higher dimensionality in quantum information is summarized.
