High-speed measurement method for diffraction efficiency of gratings in broad range wavelength based on AOTF

Diffraction efficiency is a critical indicator of grating performance. Traditional single-point measurement methods are slow, often taking several hours to generate a complete diffraction efficiency curve. Existing fast measurement techniques are limited to providing efficiency curves only within the 550-750 nm wavelength range. Therefore, this paper proposes a new high-speed measurement method that leverages an acousto-optic tunable filter (AOTF), an integrating sphere, and a concave mirror to achieve rapid and precise diffraction efficiency measurements. Experimental results demonstrate that for gratings with 300-1200 grooves per millimeter, this method can complete measurements within the 500-1000 nm wavelength range in under one minute. The mean absolute error is less than 2%, with a repeatability error also below 2%.