Topic
Spatial filter
About: Spatial filter is a research topic. Over the lifetime, 6170 publications have been published within this topic receiving 100451 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, a quasi-Gaussian profile-transmittance filter based on radially varying the phase retardation in a birefringent element has been proposed to generate an improved resonator spatial-mode profile.
Abstract: We have invented a quasi-Gaussian profile-transmittance filter based on radially varying the phase retardation in a birefringent element. The radial birefringent element has been applied to resonator design and has demonstrated its usefulness in generating an improved resonator spatial-mode profile.
61 citations
TL;DR: In this article, a new measurement technique is developed in which three single measurements of the scattered light are used to determine the volume mean diameter, area mean diameter and variance of the particle distribution regardless of the nature of the distribution.
61 citations
Patent•
31 Oct 1994TL;DR: In this article, a system for and method of enhancing image/video signals to be decoded is disclosed, which uses, preferably, a temporal filter and a spatial filter, both of which are adaptive but neither is required to be adaptive.
Abstract: A system for and method of enhancing image/video signals to be decoded is disclosed The system for and method of post-filtering uses, preferably, a temporal filter (eg, 110) and a spatial filter (eg, 112), both of which are adaptive but neither is required to be adaptive However, the system for and method of post-filtering may also be used with only an adaptive spatial post-filter In this case, the performance is upper-bounded by the performance of systems using both the adaptive temporal and adaptive spatial post-filter
61 citations
TL;DR: In this article, the characteristics of coherent array beams generated by waveguide carbon dioxide laser structures have been investigated, with particular emphasis on their propagation and transformation properties, and measurements of array beam quality are given through the use of the M/sup 2/parameter.
Abstract: The characteristics of coherent array beams generated by waveguide carbon dioxide laser structures have been investigated, with particular emphasis on their propagation and transformation properties. Methods of array beam generation are presented, and measurements of array beam quality are given through the use of the M/sup 2/ parameter. Efficient transformation of an array beam from the antisymmetric to symmetric pattern is achieved through the use of a binary phase plate, and spatial filtering is shown to improve the beam quality at the expense of only a moderate loss of total beam power. Coherence effects in the near-field propagation of array beams are also explored.
61 citations
Patent•
IBM1
TL;DR: In this article, the alignment pattern configuration permits the X, Y coordinate locations of at least two corresponding points on the mask and wafer to be sensed by scanning the filtered images of the alignment patterns in a single direction.
Abstract: An electro-optical mask and wafer alignment system employs alignment patterns on the mask and wafer whose images can be selectively passed through a spatial filter. Each pattern comprises at least two nonparallel lines. The alignment pattern configuration permits the X, Y coordinate locations of at least two corresponding points on the mask and wafer to be sensed by scanning the filtered images of the alignment patterns past a sensing device in a single direction. The mask and/or wafer are then positioned such that the signals generated from the alignment patterns indicate that the corresponding points on the mask and wafer are aligned.
61 citations