scispace - formally typeset
Search or ask a question
Topic

Angular aperture

About: Angular aperture is a research topic. Over the lifetime, 1771 publications have been published within this topic receiving 27257 citations.


Papers
More filters
Journal ArticleDOI
06 Jun 2006-Optik
TL;DR: Based on the vectorial Rayleigh-Sommerfeld diffraction integrals, analytical expressions for the transversal and axial field distribution of plane wave propagating through a thin lens followed by a small circular aperture are derived and used to study the focusing and diffraction properties of plane waves as discussed by the authors.

4 citations

Proceedings ArticleDOI
26 Nov 1996
TL;DR: In this paper, Sttetler et al. proposed an approach to optimize the shape and geometrical dimensions of laser scalpels to minimize tissue damage by means of exception of light leaking through the tapered surface and decrease of distal end inner reflection.
Abstract: The paper deals with a problem of light focusing on the tissue for laser surgery, diagnostic and therapeutics with assistance by tapered tips. Optimization of the shape and geometrical dimensions of laser scalpels sought to minimize tissue damage by means of exception of light leaking through the tapered surface and decrease of distal end inner reflection. These results can be achieved by simultaneous attaching,spherical shape to the front surface of tapered tip also optimization of fiber-tip distance and tip dimensions. Analytical and ray-tracing calculations have been performed for sapphire (n equals 1.75) and silica (n equals 1.45) tip materials and air or saline (n equals 1.33) mediums. The diameter of aperture diaphragm and reflection number of incident beam in the tip have been varied from 1 to 5 fiber core diameter and from 1 to 10, respectively. Several numerical methods for evaluation of tip efficiency for optimized and conventional tips were discussed. Some versions of commercially available tip modernization have been presented. Modification of front surface of the tapered tip increased the angular aperture from 4 degrees to 12 degrees (in air) and from 8 degrees to 15 degrees (in saline) with obviating light leaking in commercial tip by Hans Sttetler SA, Switzerland. Replacement of the contact flat laser scalpel (surgical laser technologies, Malvern, PA) to an optimized one allowed us to increase the taper angle from 1.9 degrees to 10 degrees and produced, therefore, shorter and stronger tip without reducing its optical properties.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

4 citations

Patent
24 Dec 1997
TL;DR: In this article, a source light beam is made off-perpendicularly incident on a crystal body, so that the cross section of the source lightbeam is narrowed within the crystal body.
Abstract: In a non-collinear type acousto-optic tunable filter, a source light beam is made off-perpendicularly incident on a crystal body, so that the cross section of the source light beam is narrowed within the crystal body. As a result, the receiving angular aperture becomes large to increase the amount of light collected into the crystal body. Consequently, highly accurate spectrometry can be performed even if the intensity of the source light beam is low. Further, the non-diffraction part of the crystal body can be eliminated by the off-perpendicular incidence of the source light beam, so that the sufficient diffraction length of acoustic and optic waves can be obtained.

4 citations

Patent
07 Oct 2005
TL;DR: In this paper, a compact and high resolution imaging lens array that comprises successively from the object side: a first positive lens is a meniscus plastic lens with a concave surface facing forward, a second glass biconvex lens, a third negative lens is an aspherical surface with an aperture located between the first lens and the second lens.
Abstract: The present invention relates to a compact and high resolution imaging lens array that comprises successively from the object side: a first positive lens is a meniscus plastic lens with a concave surface facing forward, a second glass biconvex lens, a third negative lens is a meniscus lens with a concave surface facing forward, a fourth positive lens is a biconvex lens made of plastic, and an aperture is located between the first lens and the second lens. The respective lenses are provided with aspherical surface, and thus the size of the imaging lens array can be reduced and the resolution also can be improved.

4 citations

Patent
22 Jun 2004
TL;DR: In this article, the authors presented an imaging lens with an F-number in the range 2.0 to 4.0, configured from only two lenses, with a short lens optical length, and with sufficiently high image contrast so that sharp images are obtained.
Abstract: The present invention relates to an imaging lens with an F-number in the range 2.0 to 4.0, configured from only two lenses, with a short lens optical length, and with sufficiently high image contrast so that sharp images are obtained. The imaging lens is configured by positioning, in order from an object side to an image side, an aperture diaphragm, a first lens, a second diaphragm, and a second lens, satisfying the following conditions. The first lens and second lens are both meniscus-shaped with convex surface facing the object side, and have positive refractive power. 0.3 < f1/f2 < 1.0 0.4 < bf/f < 0.5 1.0 < d/f < 1.3 0.12 < D2/f < 0.30 2.0 < Fno < 4.0 Here f is the combined focal length of the imaging lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, bf is the distance (in air) from the image-side surface of the second lens to the image plane, d is the distance (in air) from the object-side surface of the first lens to the image plane, D2 is the interval between the first lens and the second lens, and Fno is the F-number.

4 citations


Network Information
Related Topics (5)
Amplifier
163.9K papers, 1.3M citations
70% related
Resonator
76.5K papers, 1M citations
70% related
Photonic crystal
43.4K papers, 887K citations
69% related
Polarization (waves)
65.3K papers, 984.7K citations
69% related
Optical fiber
167K papers, 1.8M citations
68% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20234
20224
20217
20207
20195
201811