Three-Dimensional Superresolution Characteristics Of Pupil Filters

Resolution is the most important performance parameter of an imaging system. In an ideal imaging system it is determined by diffraction limit. Superresolution technique is well known for the ability of breaking through the classical diffraction limit. It has a wide application in the confocal imaging systems and the optical storage.In this dissertation, the principle of optical superresolution by pupil filters is discussed. Amplitude, phase-only and complex pupil filters are designed and the superresolution properties are studied.The analytic model of superresolution characteristic parameter with pupil filter is given based on definition of superresolution characteristic parameter From the above made model, the superresolution properties of amplitude and phase-only pupil filter are analyzed and compared. The applicable range and characteristics of different type pupil filter are shown.Complex pupil filters are introduced to improve the three-dimensional resolving power of an optical imaging system. Through the design of the essential parameters of such filters, the transmittance and radius of the first zone, three-dimensional superresolution is realized. The Strehl ratio and the transverse and axial gains of such filters are analyzed in details. A series of simulation examples of such filters are also presented that prove that three-dimensional superresolution can be realized.