The absorption coefficient, in turn, is simply related to several other quantities:

The absorption coefficient is related to the dielectric constant (especially complex term).

For a direct band gap, the absorption coefficient is related to light frequency according to the following formula:

Some example shows the negative absorption coefficient that is fundamental presentation of semiconductor laser.

The material medium will have a certain emission coefficient and absorption coefficient.

This is calculated using its dimensions and the absorption coefficients of the walls.

The absorption coefficient depends on four factors: the gas, the liquid, temperature, pressure.

Values for the absorption coefficients of several different gases in water at s.t.p. are shown in table 6.1.

This would have an absorption coefficient of 1.

Since intensity is proportional to the square of the electric field, the absorption coefficient becomes .