Analytic Design Procedure of Three-mirror Telescope Corrected for Spherical Aberration, Coma, Astigmatism, and Petzval Field Curvature

Hitachi’s Spherical Aberration Corrected STEM: HD-2700

INTRODUCTION AS VLSI (very large scale integration) technology evolves toward ever smaller features and multilayer designs, analysis and control of structures and compositions at the atomic level is becoming increasingly important. In 1998 Hitachi HighTechnologies Corporation released the HD-2000, a STEM (scanning transmission electron microscope) that was very well received for combining the e...

Generic Misalignment Aberration Patterns in Wide-Field Telescopes

Axially symmetric telescopes produce well known “Seidel” off-axis third-order aberration patterns: coma, astigmatism, curvature of field and distortion. When axial symmetry is broken by the small misalignments of optical elements, additional third-order aberration patterns arise: one each for coma, astigmatism and curvature of field and two for distortion. Each of these misalignment patterns is...

All-spherical catadioptric telescope design for wide-field imaging.

The current trend in building medium-size telescopes for wide-field imaging is to use a Ritchey-Chrétien (RC) design with a multilens corrector near the focus. Our goal is to find a cost-effective alternative design to the RC system for seeing-limited observations. We present an f/4.5 all-spherical catadioptric system with a 1.5° field of view. The system consists of a 0.8 m spherical primary a...

Compensation of corneal horizontal/vertical astigmatism, lateral coma, and spherical aberration by internal optics of the eye.

Both the anterior surface of the cornea and the internal optics (the posterior cornea, crystalline lens) contribute to the aberration of a wavefront passing through the eye. Artal, Guirao, Berrio, and Williams (2001) reported that the wavefront aberrations produced by the internal optics offset, or compensate for, the aberrations produced by the cornea to reduce ocular wavefront aberrations. We...

Contrast formation mechanism of spherical aberration corrected bright- field STEM images using a middle collection angle