Diffraction efficiency

Diffraction efficiency is the performance of diffractive optical elements – especially diffraction gratings – in terms of power throughput. It's a measure of how much optical power is diffracted into a designated direction compared to the power incident onto the diffractive element. Diffraction efficiency is the performance of diffractive optical elements – especially diffraction gratings – in terms of power throughput. It's a measure of how much optical power is diffracted into a designated direction compared to the power incident onto the diffractive element. If the diffracted power is designated with P {displaystyle P} and the incident power with P 0 {displaystyle P_{0}} the efficiency η {displaystyle eta } reads In the most common case – the diffraction efficiency of optical gratings (therefore also called grating efficiency) – there are two possibilities to specify efficiency: