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 and the incident power with the efficiency reads
- The absolute efficiency is defined as above and relates the power diffracted into a particular order to the incident power.
- The relative efficiency relates the power diffracted into a particular order to the power that would be reflected by a mirror of the same coating as the grating, therefore attributing to inevitable reflection losses at the grating but not caused by inefficient diffraction itself.
- "Diffraction Efficiency & Relationship between Diffraction Efficiency and Polarization". Shimadzu Corporation. 2012. Retrieved 1 November 2012.
- "Technical Note 10 – Guidelines for specifying diffraction gratings". Newport Corporation. Retrieved 1 November 2012.
- Christopher Palmer (2005). "Efficiency Characteristics of Diffraction Gratings". Diffraction Grating Handbook (sixth edition). Newport Corporation. Retrieved 1 November 2012.