Encyclopedia - Numerical Aperture: Encyclopedia Ii - Numerical Aperture - General Optics
In most areas of optics, and especially in microscopy, the numerical aperture of an optical system such as an objective lens is defined b...   » Read the article

Encyclopedia - Continuous Wave: Encyclopedia Ii - Continuous Wave - Radio
Very early radio transmitters used a spark gap to produce radio-frequency oscillations in the transmitting antenna; these signals had a c...   » Read the article

Encyclopedia - Numerical Aperture: Encyclopedia Ii - Numerical Aperture - Laser Physics
In laser physics, the numerical aperture is defined slightly differently. Laser beams spread out as they propagate, but slowly. Far away ...   » Read the article

Encyclopedia - Numerical Aperture: Encyclopedia Ii - Numerical Aperture - Fiber Optics
Multimode optical fiber will only propagate light that enters the fiber within a certain cone, known as the acceptance cone of the fiber....   » Read the article