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

Abstract

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%.