LSST optical beam simulator

We describe a camera beam simulator for the LSST which is capable of illuminating a 60mm field at f/1.2 with realistic astronomical scenes, enabling studies of CCD astrometric and photometric performance. The goal is to fully simulate LSST observing, in order to characterize charge transport and other features in the thick fully depleted CCDs and to probe low level systematics under realistic conditions. The automated system simulates the centrally obscured LSST beam and sky scenes, including the spectral shape of the night sky. The doubly telecentric design uses a nearly unit magnification design consisting of a spherical mirror, three BK7 lenses, and one beam-splitter window. To achieve the relatively large field the beam-splitter window is used twice. The motivation for this LSST beam test facility was driven by the need to fully characterize a new generation of thick fully-depleted CCDs, and assess their suitability for the broad range of science which is planned for LSST. Due to the fast beam illumination and the thick silicon design [each pixel is 10 microns wide and over 100 microns deep] at long wavelengths there can be effects of photon transport and charge transport in the high purity silicon. The focal surface covers a field more than sufficient for a 40x40 mm LSST CCD. Delivered optical quality meets design goals, with 50% energy within a 5 micron circle. The tests of CCD performance are briefly described.Comment: 9 pages, 9 figure

Some lens structural performance displays

Some useful displays that reveal structural performance of lens systems are presented and discussed. They are useful for gleaning into how lenses work, their problems, and their imaging potential. An imaging simulation of a square wave is also presented to complement MTF plots. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Angular Spectrum Evaluation Tool analysis of the Crown of Light diamond cut

We analyze the Crown of Light (COL) cut using an angular spectrum evaluation tool. Several light performing features of the COL are discussed. In particular, it is found that the angular spectrum of the COL tends to be concentrated and that this maximizes the brilliance and sparkle probability when the COL is aimed at localized light sources. It is contended that the COL represents a novel paradigm in diamond cuts. A distinctive feature of the COL cut is its dome shaped crown. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its.Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Method for the design of nonaxially symmetric optical systems using free-form surfaces (Erratum)

A method for the design of nonaxially symmetric optical systems using free-form surfaces is proposed by researchers. Attention was placed to have an F-number of 2.0 in both principal sections of the telescope as the RMS spot size highly depends on F-number. The distortion aberration, smile and keystone of the design is 3.36%, and there is negligible image plane tilt with respect to the optical axis ray. The researchers have corrected the error in the comparison we made in their paper by properly scaling up the three-mirror system and re-optimizing it to account for the scale change, and for the fact that the optimization of the f = 35.7 mm system was stopped earlier when it reached close to diffraction limited performance.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Improving as-built miniature lenses that use many aspheric surface coefficients with two desensitizing techniques

We present two techniques to improve as-built miniature lenses that are defined with high-order aspheric surfaces without losing optical quality and without significantly modifying the layout of the lens. We note that miniature lenses are often defined with more aspheric coefficients than needed. This redundancy can lead to poor as-built lenses. The first technique consists of gradually reducing the number of high-order aspheric coefficients while reoptimizing the lens and maintaining the performance. The second technique consists of desensitizing the lens through a multi-configuration process where different configurations are defined and optimized at the same time. These are the nominal configuration and several perturbed configurations that include lens decenter and tilt. Both techniques are shown to work for improving as-built lenses as we show in two examples from the lens literature. © 2021 Society of Photo-Optical Instrumentation Engineers (SPIE). © 2021 American Society of Civil Engineers (ASCE). All rights reserved.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Optics for the 20/20 telescope

ABSTRACT We present a plan for making the optics of a 21 m telescope that builds on advances in mirror design and fabrication developed for the Large Binocular Telescope (LBT) and other large telescopes. The 21 m telescope, with a fast f/0.7 primary mirror made of only seven large honeycomb-sandwich segments and an adaptive secondary with matching segments, is much stiffer than other designs and offers simpler and more accurate wavefront control. It can be a powerful stand-alone telescope, or one of a pair that move on a circular track to achieve coherent imaging with baselines up to 120 m (the 20/20 telescope). Each segment of the 21 m primary mirror is similar to an 8.4 m LBT primary, and each segment of the 2.1 m adaptive secondary mirror is similar to an LBT secondary. The off-axis segments of both mirrors can be made with the same methods and equipment currently used at the Steward Observatory Mirror Lab, and can be polished with the same stressed-lap polishing system used for the LBT mirrors. A change in algorithm to accommodate the asymmetric surface is required, but no new hardware development is needed because the lap bending is similar to that for the LBT mirrors. Each segment can be measured interferometrically, with a combination reflective and diffractive null corrector producing an accurate aspheric template wavefront and alignment references for the segments

Optical Interconnections Using Microlens Arrays

Free-space interconnection of widely spaced pixels may be implemented using microlenses, rather than conventional imaging. Advantages, problems, and studies of system capacity are discussed