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: In this paper, the effects of aberration on focal line features are analyzed and the authors show that source imperfection, especially the transverse velocity spread, plays a critical role in broadening the feature width.
Abstract: The image distortion which comes from aberration is analyzed and the effects on focal line features are also discussed, which are resulted from the spherical aberration, chromatic aberration and beam spread. The simulation results have show that source imperfection, especially the transverse velocity spread, plays a critical role in broadening the feature width.
2 citations
TL;DR: It is found that the non-linear corrections to aberration sensitivity decreases when geometric magnification or aberration orders increase, and the original transverse modes are mixed.
Abstract: The aberration sensitivity of unstable-cavity geometries is studied by incorporating the change of the ray path by the intra-cavity aberrations in geometric-optic approximation. The first order non-linear correction in a positive branch, confocal unstable cavity is obtained analytically. In particular, as the optic field passes through an aberration plane in which the higher order aberrations are presented, more higher order aberrations are induced on the wavefront of optic field, and the original transverse modes are mixed. This mode mixing is studied by introducing non-constant propagation matrices. Similar to the linear results, we find that the non-linear corrections to aberration sensitivity decreases when geometric magnification or aberration orders increase.
2 citations
TL;DR: In this article, the transverse spherical aberration of a thin lens is calculated and a normalized aberration Y equal to TA divided by the theoretical resolution limit is defined, where Y 1.6 is the angular norm of the Gaussian beam.
Abstract: In this paper, we calculate the transverse spherical aberration TA of a thin lens and defines a normalized aberration Y equal to TA divided by the theoretical resolution limit. As a rule of thumb, (a) a thin lens that suffers only from spherical aberration may be considered effectively diffraction-limited as long as Y 1.6, and, specifically, (c) the lens need be diffraction-limited only over a radius approximately equal to the radius (to the 1/e-point) of the Gaussian beam.
2 citations
TL;DR: In this paper , a linear imaging theory for differential phase contrast under weak-phase-weak-amplitude object approximation is proposed, where contrast transfer functions are defined for thin and thick weak objects.
2 citations
TL;DR: In this paper, an optical pickup with a spherical aberration compensator using nematic liquid crystal (LC) cells was proposed, which is composed of two LC cells each of which has X and Y stripe electrodes, respectively.
Abstract: To increase recording density in an optical disk system, a two-lens system which enlarge its numerical aperture (NA) has been developed. When NA becomes larger, however, the spherical aberration due to disk thickness error increases. We propose an optical pickup with a spherical aberration compensator using nematic liquid crystal (LC). Our LC device is composed of two LC cells each of which has X and Y stripe electrodes, respectively. We discussed how the spherical aberration due to the disk thickness error can be compensated by combination of two crossed cylindrical phase distributions induced by the LC cells, and confirmed the compensation effect in a design example by simulation. We have also fabricated the crossed stripe LC device actually, and have obtained the experimental result which shows that amount sufficient to compensate the aberration is achieved.
2 citations