Koehler integrator device and application thereof in a multi-focal confocal microscope

A Koehler integrator device, comprising

• a collimating lens being arranged for collimating a light field created by a light source device to provide a collimated light field,
• a pair of planar first and second micro-lens arrays, being arranged for relaying portions of the collimated light field along separate imaging channels, wherein all micro-lenses of the first and second micro-lens arrays have an equal micro-lens focal length and pitch and the micro-lens arrays are arranged with a mutual distance equal to the micro-lens focal length,
• a collecting Fourier lens having a Fourier lens diameter and a Fourier lens focal length defining a Fourier lens front focal plane and a Fourier lens back focal plane, wherein the Fourier lens is arranged for superimposing light from all imaging channels in the Fourier lens front focal plane and wherein the second micro-lens array is arranged in the Fourier lens back focal plane, and
• a third micro-lens array being arranged in the Fourier lens front focal plane for creating a wavelength independent array of illumination spots.