Broad‐Bandwidth Micro‐Diffractive Optical Elements

Abstract Thin, lightweight micro‐diffractive optical elements (M‐DOEs) are of great significance to integrated optics. However, the narrow working bandwidth of M‐DOEs allows them to operate only at specific wavelengths. Existing solutions require multiple components assembly, which is difficult to implement in an integrated system. Here, a general designing and processing scheme of an optofluidic‐integrated broad‐bandwidth M‐DOE is reported, achieving an average diffraction efficiency of over 84% across the entire visible band (406–824 nm). As a proof‐of‐concept, a wideband operating micro‐diffractive lens and orbital angular momentum beam micro‐generator are demonstrated. This strategy provides a common protocol for various broad‐bandwidth M‐DOEs operating in integrated optical systems.