How do you calculate Strehl ratio?
The Strehl ratio is a measure of the quality of optical image formation. The Strehl ratio equals the exponential of -4\[Pi] squared times the root mean square deviation of the wavefront squared divided by the wavelength squared.
What is a good Strehl ratio?
When designing an optical system, the Strehl ratio is used to estimate the required correction of wavefront aberrations. The acceptable level of wavefront aberrations is different for every application but a value of 0.80 Strehl is conventionally used to define an optical system as “Diffraction limited” or ideal.
What is RMS wavefront error?
RMS Wavefront Error in Zemax
The errors are the difference between the actual wavefront and the ideal spherical wavefront converging on the image point. In a system with aberrations, rays from different positions in the exit pupil may miss the ideal image position by various amounts when they reach the image plane.