free-space propagation
111Communications optiques en espace libre — Laser optique 8 faisceaux en espace libre, assurant un lien de débit 1Gbits/s à une distance approximative de 2km. Le récepteur est constitué du large disque central, l émetteur des 8 petits disques latéraux. En haut à droite, un objectif… …
112Planck units — are units of measurement named after the German physicist Max Planck, who first proposed them in 1899. They are an example of natural units, i.e. units of measurement designed so that certain fundamental physical constants are normalized to 1. In …
113Radio — is the transmission of signals, by modulation of electromagnetic waves with frequencies below those of visible light.Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of… …
114Spontaneous emission — is the process by which a light source such as an atom, molecule, nanocrystal or nucleus in an excited state undergoes a transition to the ground state and emits a photon. Spontaneous emission of light or luminescence is a fundamental process… …
115Antenna measurement — techniques refers to the testing of antennas to ensure that the antenna meets specifications or simply to characterize it. Typical parameters of antennas are gain, radiation pattern, beamwidth, polarization, and impedance.The antenna pattern is… …
116Theoretical and experimental justification for the Schrödinger equation — The theoretical and experimental justification for the Schrödinger equation motivates the discovery of the Schrödinger equation, the equation that describes the dynamics of nonrelativistic particles. The motivation uses photons, which are… …
117liquid crystal — a liquid having certain crystalline characteristics, esp. different optical properties in different directions when exposed to an electric field. [1890 95] * * * Substance that flows like a liquid but maintains some of the ordered structure… …
118Bluetooth — This article is about the electronic protocol. For the medieval King of Denmark, see Harald I of Denmark. Bluetooth logo Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances (using short wavelength …
119Citizens' band radio — Typical 1980s CB base station, used with outdoor antenna. This radio may also be used in an automobile, since it is powered by 13.8V DC. Shown with Astatic Power D 104 desk mic …
120Ray transfer matrix analysis — (also known as ABCD matrix analysis) is a type of ray tracing technique used in the design of some optical systems, particularly lasers. It involves the construction of a ray transfer matrix which describes the optical system; tracing of a light… …
