Topic
Diffraction efficiency
About: Diffraction efficiency is a research topic. Over the lifetime, 10320 publications have been published within this topic receiving 158298 citations.
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TL;DR: In this article, the formation of surface relief structures in azobenzene polyesters formed by polarization holography with orthogonally circularly polarized laser beams was examined in detail.
Abstract: We have examined in detail the formation of surface relief structures in azobenzene polyesters formed by polarization holography with orthogonally circularly polarized laser beams. We show that it is possible to separate the contribution to the diffraction efficiency into an anisotropic part and a surface relief part by examining the polarization content of the first order diffracted beam. By studying the dynamics of the growth of the grating, we show that the gratings due to anisotropy and surface relief appear at the same time. Atomic force microscopic investigations of the film after irradiation reveal a strongly polarization dependent surface relief pattern.
137 citations
TL;DR: Reflection gratings produced entirely of dielectric materials give the opportunity to enhance the laser damage threshold over that occurring in conventional metal gratings used for chirped-pulse-amplification, high-power lasers.
Abstract: We report on reflection gratings produced entirely of dielectric materials. This gives the opportunity to enhance the laser damage threshold over that occurring in conventional metal gratings used for chirped-pulse-amplification, high-power lasers. The design of the system combines a dielectric mirror and a well-defined corrugated top layer to obtain optimum results. The rules that have to be considered for the design optimization are described. We optimized the parameters of a dielectric grating with a binary structure and theoretically obtained 100% reflectivity for the -1 order in the Littrow mounting for a 45° angle of incidence. Subsequently we fabricated gratings by structuring a low-refractive-index top layer of a multilayer stack with electron-beam lithography. The multilayer system was fabricated by conventional sputtering techniques onto a flat fused-silica substrate. The parameters of the device were measured and controlled by light scatterometer equipment. We measured 97% diffraction efficiency in the -1 order and damage thresholds of 4.4 and 0.18 J/cm2 with 5-ns and 1-ps laser pulses, respectively, at a wavelength of 532 nm in working conditions.
136 citations
Patent•
20 Jun 1995TL;DR: The diffractive optical modulator of as discussed by the authors consists of a plate having a portion functioning as a first electrode, a spacer layer formed on the plate, and a grating consisting of a plurality of beams having a part functioning as second electrode, both ends of the beams being supported on the spacer.
Abstract: The diffractive optical modulator of the invention includes: a plate having a portion functioning as a first electrode; a spacer layer formed on the plate; and a grating consisting of a plurality of beams having a portion functioning as a second electrode, both ends of the beams being supported on the spacer layer. In the diffractive optical modulator, by adjusting a voltage applied between the first electrode and the second electrode, a distance between the beams and the plate is varied, thereby controlling the diffraction efficiency. An insulating layer is further provided between the plate and the plurality of beams.
135 citations
TL;DR: The achievement of a neat and compact MMM is described by use of a high-diffraction-efficiency diffractive-optic element that generates a multiple-spot grid of uniform intensity to achieve higher fidelity in imaging of live cells at adequate speeds.
Abstract: Multiphoton multifocal microscopy (MMM) usually has been achieved through a combination of galvo scanners with microlens arrays, with rotating disks of microlens arrays, and cascaded beam splitters with asynchronous rastering of scanning mirrors. Here we describe the achievement of a neat and compact MMM by use of a high-diffraction-efficiency diffractive-optic element that generates a multiple-spot grid of uniform intensity to achieve higher fidelity in imaging of live cells at adequate speeds.
135 citations
01 Mar 1991
TL;DR: In this article, the dispersion property of diffractive optical elements is exploited to solve a number of optical design problems that are difficult or impossible to solve with conventional refractive and reflective elements.
Abstract: : Diffractive optical elements are being considered as potential solutions to a number of optical design problems that are difficult or impossible to solve with conventional refractive and reflective elements. Two unique characteristics of diffractive elements can be exploited; the first is teh dispersion property. Diffractive structures bend light rays of longer wavelengths more than those of shorter wavelengths, which is the reverse of refractive materials; therefore, diffractive structures minimize or eliminate the dispersive effects of refractive materials. The second unique characteristic is the relative ease with which arbitrary phase profiles can be implemented. Advances in both diamond turning technology and the use of semiconductor fabrication equipment have made possible the construction of a variety of diffractive elements. Diamond turning technology allows fabricating diffractive surfaces over large areas in a relatively short period of time. However, there are limitations: the phase profile has to be circularly symmetric, and the accuracy with which a diffractive profile can be made is dependent on the tip size of the diamond turning tool. Using semiconductor fabrication equipment to make diffractive elements has become a powerful technique. This particular approach produces a stepped approximation, referred to as a multilevel structure, to the ideal profile.
135 citations