BEYOND THE CONVENTIONAL INFORMATION LIMIT - THE RELEVANT COHERENCE FUNCTION

The theory of partial coherence functions as applied to a super-resolu tion reconstruction algorithm is developed in detail, taking into acco unt the phase gradients across the aperture function, the source and d etector sizes, and temporal coherence. Experimental examples demonstra te the main properties of the relevant coherence envelopes, and why th ey need not limit the total band-pass of the microscope. It is demonst rated that finite detector size in the STEM configuration can facilita te a simpler reconstruction algorithm by creating a virtual objective aperture which obviates the need for a physical objective aperture. Th ese results are also relevant to the question of uniquely deconvolving shadow images.