Topic
Angular aperture
About: Angular aperture is a research topic. Over the lifetime, 1771 publications have been published within this topic receiving 27257 citations.
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Patent•
30 Apr 1998
TL;DR: In this paper, the authors proposed a wide-angle lens system for longitudinal chromatic aberration correction without recourse to any anomalous dispersion glass while a long enough back focus is fully ensured.
Abstract: The invention provides an inexpensive wide-angle lens system which is well corrected for longitudinal chromatic aberration and chromatic aberration of magnification without recourse to any anomalous dispersion glass while a long enough back focus is fully ensured. The wide-angle lens system comprises a front lens group comprising at least one positive lens and having negative power as a whole, an aperture stop 10, and a rear lens group comprising at least one negative lens and a diffractive optical element 11 having a diffractive surface of positive power, and having positive power as a whole, and satisfies 0.005
23 citations
TL;DR: In this article, a generalization of Ludwig's (1973) third definition that introduces a /spl theta/-dependence that is absent from Ludwig's original definition is presented. But this generalization is based on the nonconformal mapping between the electric field vector lying in the propagation plane (i.e., the probe aperture plane) and the projection of this vector onto the aperture plane (e.g., the AUT aperture plane).
Abstract: This article presents a generalization of Ludwig's (1973) third definition that introduces a /spl theta/-dependence that is absent from Ludwig's original definition. Our generalization is based on the nonconformal mapping between the electric field vector lying in the propagation plane (i.e., the probe aperture plane) and the projection of this vector onto the aperture plane (i.e., the AUT aperture plane). We show the error incurred by the two definitions for both the E-field and the H-field aperture models. Ludwig's definition incurs the same level of error for both models while our generalized definition incurs slightly more error for the H-field aperture model but no error for the E-field aperture model.
23 citations
TL;DR: In this paper, the diffraction characteristics of a broadband light source from a circular aperture in the far field are clarified theoretically via a prompt and precise mathematical derivation, and a rig-orous treatment of a time-variant Gaussian-shaped pulsed beam pass- ing through a circle aperture is provided.
Abstract: The diffraction characteristics of a broadband light source from a circular aperture in the far field are clarified theoretically via a prompt and precise mathematical derivation. We provide not only a rig- orous treatment of a time-variant Gaussian-shaped pulsed beam pass- ing through a circular aperture, but also give a more accurate and con- crete determination of light distributions including the spectral, time- space intensity, and energy distributions. © 2002 Society of Photo-Optical
23 citations
Patent•
14 Mar 1997TL;DR: In this article, an optical disc system with a light-transmitting cover and an objective lens for bundling or focusing a light beam on a recording layer of the optical disc is presented.
Abstract: An optical disc system uses an optical disc with a light-transmitting cover and an objective lens for bundling or focusing a light beam on a recording layer of the optical disc in order to perform recording and/or reproducing of information. The thickness of the light-transmitting cover falls within the range of 0.05 mm to 0.6 mm, the numerical aperture (NA) of the objective lens is set to fall within the range of 0.55 to 1.10, and the wavelength of the light beam is selected to be between 100 nm to 780 nm.
23 citations
TL;DR: In this paper, the relation between the electron diffraction pattern and the Fourier transform pattern of the image of a crystal of varying thickness is discussed, in which weak phase object approximation and dynamic scattering object are considered.
23 citations