Topic
Contrast transfer function
About: Contrast transfer function is a research topic. Over the lifetime, 934 publications have been published within this topic receiving 26533 citations.
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TL;DR: A method for the measurement of third-order spherical aberration coefficients (C(s)), using low-order zone-axis Ronchigrams of a crystalline material, and a method for roughly estimating defocus values is presented.
14 citations
TL;DR: A method that first obtains both the physical thickness and the refractive index of the aberration inducing medium in situ by measuring the induced focal shifts for paraxial and large angle rays and uses the fourth order angle dependence of the optical path difference inside the medium to correct the spherical aberration.
Abstract: In imaging and focusing applications, spherical aberration induces axial broadening of the point spread function (PSF). A transparent medium between lens and object of interest induces spherical aberration. We propose a method that first obtains both the physical thickness and the refractive index of the aberration inducing medium in situ by measuring the induced focal shifts for paraxial and large angle rays. Then, the fourth order angle dependence of the optical path difference inside the medium is used to correct the spherical aberration using a phase-only spatial light modulator. The obtained measurement accuracy of 3% is sufficient for a complete compensation as demonstrated in a model microscope with NA 0.3 with glass plate induced axial broadening of the PSF by a factor of 5.
14 citations
TL;DR: The MAD-LEEM approach images the DNA with low electron impact energies, which provides nucleobase contrast mechanisms without organometallic labels, and the micron-size field of view when combined with imaging on the fly provides long read lengths, thereby reducing the demand on assembling the sequence.
14 citations
Patent•
02 May 1985TL;DR: Stripe patterns of varying spatial frequency, formed in the top-metalization of a back-illuminated solid-state imager, facilitate on-line measurement of contrast transfer function during wafer-probe testing.
Abstract: Stripe patterns of varying spatial frequency, formed in the top-metalization of a back-illuminated solid-state imager, facilitate on-line measurement of contrast transfer function during wafer-probe testing. The imager may be packaged to allow front-illumination during in-the-field testing after its manufacture.
14 citations
TL;DR: Computer simulations are presented, demonstrating recovery of the terraced height profile of atomic steps, using phase retrieval to decode a single LEEM image, incorporating the effects of defocus, spherical aberration and chromatic aberration.
14 citations