Abstract

Partially coherent imaging performance of the scanning microscope is considered, and a scanning microscope using tilted illumination is proposed. It is known that no matter how an object is illuminated and confined, the maximum spatial frequency with which an optical image can be formed in an optical system is fixed and can be determined only by its optical pupil function. However, better restoration of the detail to a diffraction-limited image can be achieved by means of a properly designed object stop, point detector, movement of the object, and partially coherent illumination. It has been proved that superresolution can be achieved not only in the case of low Shannon numbers but in the case of high Shannon numbers provided the object details to be resolved are nonperiodic. The imaging of a two-point object and a sinusoidal distribution object is discussed in particular. The effect of different arrangements using lenses with different pupil functions is also discussed.

© 1988 Optical Society of America