METHODS FOR ABERRATION CORRECTION IN HIGH NUMERICAL APERTURE OPTICAL SYSTEMS

Described herein is a wavelength dispersive optical system (10). The system (10) comprises at least one optical input (12, 14, 16) for projecting an input optical beam comprising a plurality of individual wavelength components and at least one optical output (18) for receiving one or more output optical beams. The system (10) also includes a diffractive optical element (DOE) (1) including a substrate (2) and an array of physical diffraction elements (3). The diffraction elements (3) have a predefined spacing and/or curvature across a length of the DOE (1) and are collectively adapted to: i) spatially separate the individual wavelength components within the input optical beam to be formed into the one or more output optical beams; ii) impose predefined phase changes to the wavelength components to at least partially correct for optical aberrations to the input optical beam; and iii) impose predefined phase changes to the wavelength components to apply a wavelength dependent optical focusing to at least some of the wavelength components. The system (10) further includes an optical focusing element (5) having optical focusing properties complementary to the DOE (1) to modify the wavelength-dependent optical focusing of the wavelength components by the DOE (1).