what is the symbol for wavelength called
(5) The name intensity, symbol I, is usually used in discussions involving collimated beams of light, as in applications of the Lambert-Beer law for spectrometric analysis. (6) Spectral quantities may also be defined with respect to frequency v, or wavelength Î»; see spectral radiant energy density above. (7) Fluence is used in photochemistry to specify the energy delivered in a given time interval (for instance by a laser pulse). This quantity may also be called radiant exposure.