Method Of And Optical System For Illuminating A Sample Surface

Various embodiments may provide a method of illuminating a sample surface. The method may include arranging an illumination subsystem, the illumination subsystem including an optical source and at least one lens, having an optic axis at an incident angle greater than 0° and less than 90° to a normal of the sample surface such that a reference illumination distribution is directly generated on the sample surface based on optical light emitted by the illumination subsystem. The method may also include arranging an adjustment optical subsystem such that an adjusted illumination distribution which is more symmetrical compared to the reference illumination distribution is generated on the sample surface based on optical light emitted by the illumination subsystem.