PHASE-MODULATION EFFECTS ON THE MODULATION TRANSFER-FUNCTION OF A BINOCULAR OBJECTIVE

We investigated the phase modulation effects on the modulation transfe r functions (MTFs) of a binocular objective system made in Korea. The MTFs were measured for fields of view (FOV) of 0 degrees and 1.5 degre es. The phase modulation was carried out by giving a phase retardation pi to the aperture. The area where the phase was not retarded was of a double annular type. The MTF curves for the phase-modulated aperture were compared with those for an unmodulated aperture. We found an abe rration-compensation effect in the aberration-loaded system. The resul ts of this research indicate that the performance of many optical syst ems can be improved without any loss of light energy by properly modul ating the phase on the aperture.