OPTIMIZED SAMPLING SCHEMES FOR OFF-AXIS HOLOGRAPHY

Optimum sampling schemes are proposed for digital processing of an off-axis electron hologram. Using these sampling schemes, we can process a wider area of the hologram by digitizing at lower magnification using the same image digitizer. Using these sampling schemes, we can reduce the necessary electron dose and thus irradiation damage, because we can take a hologram at a lower magnification. A practical procedure is also proposed to reduce an effect called leakage for aberration correction from an off-axis hologram taken of a crystal specimen.