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).
metre. n. 1. (Units) a metric unit of length equal to approximately 1.094 yards. 2. (Units) the basic SI unit of length; the length of the path travelled by light in free space during a time interval of 1/299 792 458 of a second.