**harmonic plane** — The zero adopted by the United States Coast and Geodetic Survey of the Department of Commerce upon which its tidal tables, charts, and maps are based. It is an arbitrary plane, and, in Puget Sound, is the lowest plane of the tide recognized by… … Black's law dictionary

**Plane wave expansion method** — (PWE) refers to a computational technique in Electromagnetics,solve the Maxwell s equations by formulating an Eigenvalue problem out of it. This method isa popular among Photonic Crystal community, as a method of solving for the band structure… … Wikipedia

**Harmonic number** — The term harmonic number has multiple meanings. For other meanings, see harmonic number (disambiguation) .In mathematics, the n th harmonic number is the sum of the reciprocals of the first n natural numbers::H n=… … Wikipedia

**Surface second harmonic generation** — is a method for probing interfaces in atomic and molecular systems. In second harmonic generation (SHG), the light frequency is doubled, essentially converting two photons of the original beam of energy E into a single photon of energy 2 E as it… … Wikipedia

**Projective harmonic conjugates** — is defined by the following harmonic construction::“Given three collinear points A, B, C, let L be a point not lying on their join and let any line through C met LA, LB at M, N respectively. If AN and BM met at K , and LK meets AB at D , then D… … Wikipedia

**Second harmonic generation** — (SHG; also called frequency doubling) is a nonlinear optical process, in which photons interacting with a nonlinear material are effectively combined to form new photons with twice the energy, and therefore twice the frequency and half the… … Wikipedia

**Simple harmonic motion** — is the motion of a simple harmonic oscillator, a motion that is neither driven nor damped. The motion is periodic, as it repeats itself at standard intervals in a specific manner described as being sinusoidal, with constant amplitude. It is… … Wikipedia

**Complex plane** — Geometric representation of z and its conjugate in the complex plane. The distance along the light blue line from the origin to the point z is the modulus or absolute value of z. The angle φ is the argument of z. In mathematics … Wikipedia

**Gas in a harmonic trap** — The results of the quantum harmonic oscillator can be used to look at the equilibrium situation for a quantum ideal gas in a harmonic trap, which is a harmonic potential containing a large number particles that do not interact with each other… … Wikipedia

**S plane** — In mathematics and engineering, the S plane is the name for the complex plane on which Laplace transforms are graphed. It is a mathematical domain where, instead of viewing processes in the time domain modelled with time based functions, they are … Wikipedia