A polarizer or polariser is an optical filter that lets light of a specific polarization pass and blocks waves of other polarizations. It can convert a beam of light of undefined or mixed polarization into a beam of well-defined polarization, that is polarized light. The common types of polarizers are linear polarizers and circular polarizers.
Length is a measure of one dimension, whereas area is a measure of two dimensions (length squared) and volume is a measure of three dimensions (length cubed).In most systems of measurement, the unit of length is a base unit, from which other units are defined.ength is a measure of one dimension, whereas area is a measure of two dimensions (length squared) and volume is a measure of three dimensions (length cubed).
Definition of length for Students. 1  1 : the measured distance from one end to the other of the longer or longest side of an object. 2  2 : a measured distance The road is three miles in length. 3  3 : the amount of time something takes The movie is two hours in length.  4 : a piece of something that is long She bought a length of pipe.