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 novel unstable resonator configuration is described in which the field limiting aperture in a negative branch unstable resonators acts as a spatial filter to shape an almost gaussian beam and to cool the hot focal point inside the cavity down to non-damage limits.
99 citations
TL;DR: In this article, a spatial filter was used to suppress oscillation of the highest order mode of an array of AlGaAs diode lasers, and the mode was observed to be stable up to the maximum rated drive current for the device.
Abstract: Coherent operation of an array of AlGaAs diode lasers was obtained by placing the array in an external cavity which made use of the Talbot self‐imaging effect to couple the laser diodes together. A spatial filter was required to suppress oscillation of the highest order mode of the array. This filter introduced no significant loss to the cavity mode, and the mode was observed to be stable up to the maximum rated drive current for the device.
98 citations
Patent•
15 Oct 1993
TL;DR: In this paper, a holographic probe is used to measure radiative effects such as Raman scattering or fluorescence of a remotely disposed sample, and a substantially in-line path between the sample and an output optic where a narrowband reflective element, preferably holographically recorded, was used to fold excitation energy from an illumination path into the collection path.
Abstract: A holographic probe facilitates the measurement of radiative effects such as Raman scattering or fluorescence of a remotely disposed sample. Improving upon prior-art techniques, the probe teaches a substantially in-line path between the sample and an output optic wherein a narrowband reflective element, preferably holographically recorded, is used to fold excitation energy from an illumination path into the collection path and reject any Rayleigh scattering received from the sample. The improved configuration further allows a dispersive filtering element to be placed in the illumination path, which may be used in conjunction with spatial filtering to reject non-excitation wavelengths.
98 citations
TL;DR: This report reports, for the first time to the authors' knowledge, experimental demonstration of wave-front analysis via the Hartmann technique in the extreme ultraviolet range using a spatially unfiltered incident beam to characterize a sensor.
Abstract: We report, for the first time to our knowledge, experimental demonstration of wave-front analysis via the Hartmann technique in the extreme ultraviolet range. The reference wave front needed to calibrate the sensor was generated by spatially filtering a focused undulator beam with 1.7- and 0.6-microm-diameter pinholes. To fully characterize the sensor, accuracy and sensitivity measurements were performed. The incident beam's wavelength was varied from 7 to 25 nm. Measurements of accuracy better than lambdaEUV/120 (0.11 nm) were obtained at lambdaEUV = 13.4 nm. The aberrations introduced by an additional thin mirror, as well as wave front of the spatially unfiltered incident beam, were also measured.
97 citations
01 Dec 1990
TL;DR: Spatial heterodyne spectroscopy (SHS) employing a two-beam dispersive interferometer producing a Fizeau fringe pattern having wavelength-dependent spatial frequencies is presented in this paper.
Abstract: Spatial heterodyne spectroscopy (SHS) employing a two-beam dispersive interferometer producing a Fizeau fringe pattern having wavelength-dependent spatial frequencies is presented. The pattern is recorded on an imaging detector and Fourier transformed to recover the input stream. It is pointed out that spectrometers operating on the SHS principle can achieve the theoretical resolution limit of the gratings without scanning, retaining at the same time the large angular input tolerance and multiplexing properties of conventional scanning Fourier-transform spectrometers. Additionally, broad spectral coverages can be achieved, and field widening can be accomplished without moving parts.
97 citations