The optical performance test of lightweight primary mirror of space Cassegrain telescope

2013 ◽  
Author(s):  
Wei-Cheng Lin ◽  
Shenq-Tsong Chang ◽  
Ting-Ming Huang ◽  
Ming-Ying Hsu ◽  
Yu-Chuan Lin
Keyword(s):  
Performance Test ◽  
Optical Performance ◽  
Primary Mirror ◽  
Cassegrain Telescope

scholarly journals The Instruments of H.E. Dall

1988 ◽  
Vol 98 ◽  
pp. 46-47
Author(s):  
E.J. Hysom
Keyword(s):  
Numerical Aperture ◽  
Science Museum ◽  
Optical Performance ◽  
World War ◽  
Primary Mirror ◽  
World War 2 ◽  
Insufficient Time ◽  
Cassegrain Telescope ◽  
Working Distance ◽  
Prolate Ellipsoidal

In 1926 Horace Dall commenced optical work, with interests covering both microscopes and telescopes. Soon (1928), he was making solid eyepieces of the Tolles type. Eventually he developed skills in making lenses of the smallest size to be incorporated into microscope objectives of the highest numerical aperture; this culminated in an objective with a N.A. of 1.92 (a record). The lenses were jewelled elements worked with diamond dust. During World War 2 he repaired all the microscope lenses damaged in the U.K. that had originated with the German firm of Leitz.Horace Dall had an exceptionally inventive mind – and was so active in developing his ideas that he had insufficient time to formally write them up, hence much of his work remains unpublished. He did, however, keep extensive notebooks of his researches into optics. These, along with many prototypes, are now in the custody of the Science Museum, London. Combining his interests in travel, optics, and astronomy, Dall developed a number of portable, ultra-lightweight telescopes. He discovered that by incorporating what is in effect a long working distance, low-power microscope with a Cassegrain telescope he had an instrument with several advantages. The image was erect, the secondary small, and by use of a suitably placed internal stop, sky-flooding was eliminated without the use of shade tubes. Always looking for improvements in optical performance he hit on the idea of modifying the classical Cassegrain telescope by employing a prolate ellipsoidal primary mirror with a spherical secondary: independently discovered by Kirkham in the U.S.A. the type is now universally known as the Dall-Kirkham.

Silicon nanostructure-doped polymer/nematic liquid crystal composites for low voltage-driven smart windows

2021 ◽  
Author(s):  
Zemin He ◽  
Ping Yu ◽  
Huimin Zhang ◽  
Yuzhen Zhao ◽  
Yanfang Zhu ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Polymer Matrix ◽  
Performance Test ◽  
Low Voltage ◽  
Sio2 Nanoparticles ◽  
Silicon Nanostructures ◽  
Driving Voltage ◽  
Optical Performance ◽  
Smart Windows

Abstract In this work, two silicon nanostructures were doped into polymer/nematic liquid crystal composites to regulate the electric-optical performance. Commercial SiO2 nanoparticles and synthesized thiol polyhedral oligomeric silsesquioxane (POSS-SH) were chosen as the dopants to afford the silicon nanostructures. SiO2 nanoparticles were physically dispersed in the composites and the nanostructure from POSS-SH was implanted into the polymer matrix of the composites via photoinduced thiol-ene crosslinking. SEM results indicated that the implantation of POSS microstructure into the polymer matrix was conducive to obtaining the uniform porous polymer microstructures in the composites while the introduction of SiO2 nanoparticles led to the loose and heterogeneous polymer morphologies. The electric-optical performance test results also demonstrated that the electric-optical performance regulation effect of POSS microstructure was more obvious than that of SiO2 nanoparticles. The driving voltage was reduced by almost 80% if the concentration of POSS-SH in the composite was nearly 8 wt% and the sample could be completely driven by the electric field whose voltage was lower than the safe voltage for continuous contact (24 V). This work could provide a creative approach for the regulation of electric-optical performance for polymer/nematic liquid crystal composites and the fabrication of low voltage-driven PDLC films for smart windows.

A Study on the Adhesive Effects on the Optical Performance of the Primary Mirror System of a Satellite Camera

2007 ◽  
Vol 51 (6) ◽  
pp. 1901 ◽  
Author(s):  
Yu-Deok Seo ◽  
Hyun-Jung Kim ◽  
Sung-Kie Youn ◽  
Seung-Hoon Lee ◽  
Deog-Gyu Lee ◽  
...  
Keyword(s):  
Mirror System ◽  
Optical Performance ◽  
Primary Mirror

SOFIA primary mirror assembly: structural properties and optical performance

2003 ◽  
Author(s):  
Hermann Bittner ◽  
Matthias Erdmann ◽  
Peter Haberler ◽  
Karl-Heinz Zuknik
Keyword(s):  
Structural Properties ◽  
Optical Performance ◽  
Primary Mirror

SIRTF-CTA optical performance test

2003 ◽  
Author(s):  
John P. Schwenker ◽  
Bernhard R. Brandl ◽  
William Burmester ◽  
Joseph L. Hora ◽  
Amanda K. Mainzer ◽  
...  
Keyword(s):  
Performance Test ◽  
Optical Performance

SIRTF-CTA optical performance test results

2003 ◽  
Author(s):  
John P. Schwenker ◽  
Bernhard R. Brandl ◽  
William F. Hoffmann ◽  
Joseph L. Hora ◽  
Amanda K. Mainzer ◽  
...  
Keyword(s):  
Performance Test ◽  
Test Results ◽  
Optical Performance

scholarly journals An Optical Design for an Antarctic 2 m Telescope with a Near IR Imager

2002 ◽  
Vol 19 (3) ◽  
pp. 301-305 ◽  
Author(s):  
P. R. Gillingham
Keyword(s):  
Optical Design ◽  
Detector Array ◽  
Optical Performance ◽  
Primary Mirror ◽  
Low Level ◽  
Near Ir ◽  
Field Curvature ◽  
Ir Imager ◽  
Extraneous Radiation

AbstractA study has been made of the optical performance to be expected from an Antarctic Ritchey Chrétien telescope with a 2 m diameter primary mirror imaging directly onto a detector array in the K and L infrared windows. Near diffraction limited performance is provided across a flat 30 arcmin diameter field by compensating the astigmatism and field curvature with a meniscus lens which also serves as the Dewar window. With baffling inside and Narcissus mirrors outside the Dewar, extraneous radiation can be kept to a low level.

On the Use of Electrostrictive Actuators in Recovering the Optical Performance of the Hubble Space Telescope

1994 ◽  
Vol 360 ◽  
Author(s):  
James L. Fanson
Keyword(s):  
Hubble Space Telescope ◽  
Spherical Aberration ◽  
Wide Field ◽  
Optical Performance ◽  
Space Telescope ◽  
Jet Propulsion ◽  
Primary Mirror ◽  
Optical Correction ◽  
Active Mirror ◽  
Multilayer Actuators

AbstractThis paper describes the development of a space qualified active mirror—the Articulating Fold Mirror—which forms part of the scheme for recovering the optical performance of the Hubble Space Telescope. Three Articulating Fold Mirrors are incorporated into the optical train of the Jet Propulsion Laboratory's Wide Field and Planetary Camera-2, which was installed into Hubble by astronauts in December, 1993. Each Articulating Fold Mirror utilizes six electrostrictive ceramic multilayer actuators to precisely position a mirror in tip and tilt in order to correct the spherical aberration of the Hubble Space Telescope's primary mirror. Flight qualification aspects of the electrostrictive actuators are described. Pre- and postrepair images from the Wide Field and Planetary Camera, showing the effect of the optical correction, are presented.

Comparing optical test methods for a lightweight primary mirror of a space-borne Cassegrain telescope

2014 ◽  
Vol 25 (9) ◽  
pp. 094014 ◽  
Author(s):  
Wei-Cheng Lin ◽  
Shenq-Tsong Chang ◽  
Zong-Ru Yu ◽  
Yu-Chuan Lin ◽  
Cheng-Fong Ho ◽  
...  
Keyword(s):  
Test Methods ◽  
Primary Mirror ◽  
Optical Test ◽  
Cassegrain Telescope
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