Abstract: The invention relates to an optical system for providing on-axis destructive interference of light received from an object along a predetermined system optical axis. The system comprises a receiving and guiding optical structure and a combining optical structure. The receiving and guiding optical structure is for receiving and guiding at least three beams of light received from said object, the receiving and guiding optical structure arranged to provide a relative optical path difference between the at least three beams; the combining optical structure is for combining the at least three beams. According to the invention, a polarization varying optical structure is arranged between the receiving and guiding optical structure and the combining optical structure, for varying a polarization state of the beams relative to each other in order to provide on-axis destructive interference.

Abstract: The invention relates to an optical system for providing on-axis destructive interference of light received from an object along a predetermined system optical axis. The system comprises a receiving and guiding optical structure and a combining optical structure. The receiving and guiding optical structure is for receiving and guiding at least three beams of light received from the receiving and guiding optical structure arranged to provide a relative optical path difference between the at least three beams; the combining optical structure is for combining the at least three beams. According to the invention, a polarization varying optical structure is arranged between the receiving and guiding optical structure and the combining optical structure, for varying a polarization state of the beams relative to each other in order to provide on-axis destructive interference.