far-field(radiation field,far field :fraunhofer region= (german Fernfeld) : the region where the angular field distribution is
esentially independent of distance from source

Definition a measure of the light-accepting property of an optical fibre

Reference Fiberoptic Sensor Technology Handbook,OPTECH,Herndon,VA,USA,1986
(1)
ABBREV NA

Reference DA Hill,Fiber Optics,London,1977,p.32

Note {DOM} Electronics:Optoelectronic/optic components:Optic fibres and accessories
{GRM} n.p.
{NTE} the sine of the vertex angle of the largest cone of meridional rays that can enter or leave an optical system or element,multiplied by the refractive index of the medium in which the vertex of the cone is located.Generally measured with respect to an object or image point and will vary as that point is moved
(2)
TERM numerical aperture

Reference Fiberoptic Sensor Technology Handbook,OPTECH,Herndon,VA,USA,1986;Tech Term;DA Hill,Fiber Optics,London,1977,p.32

Note {DOM} Electronics:Optoelectronic/optic components:Optic fibres and accessories
{GRM} n.p.
{NTE} the sine of the vertex angle of the largest cone of meridional rays that can enter or leave an optical system or element,multiplied by the refractive index of the medium in which the vertex of the cone is located.Generally measured with respect to an object or image point and will vary as that point is moved


Definition Vermögen des Lichtleiters,Licht abzustrahlen

Reference Siemens,Begriffe der Lichtwellenleiter-Übertragungstechnik,S1
(1)
TERM numerische Apertur

Reference Siemens,Begriffe der Lichtwellenleiter-Übertragungstechnik,S1

Note {DOM} Elektronik:optoelektronische/optische Bauelemente:Lichtwellenleiter und Zubehör,in der Praxis bezeichnet man als numerische Apertur den Sinus eines geeigneten definierten Öffnungswinkels

Die numerische Apertur ist das Produkt aus dem Brechungsindex und der Apertur (Ref.: A. Kucera, The Compact Dictionary of Exact Science and Technology). Je größer die NA ist, desto mehr Listleistung kann in einen Lichtwellenleiter eingekoppelt werden.

MfG

Dipl.-Ing. Rainer Pawellek