Active optics and modified-Rumsey wide-field telescopes: MINITRUST demonstrators with vase- and tulip-form mirrors

2005 ◽  
Vol 44 (34) ◽  
pp. 7322 ◽  
Author(s):  
Gérard R. Lemaître ◽  
Pierre Montiel ◽  
Patrice Joulié ◽  
Kjetil Dohlen ◽  
Patrick Lanzoni
Keyword(s):  
Author(s):  
Gérard Rene Lemaitre

AbstractActive optics techniques on large telescopes and astronomical instrumentations provide high imaging quality. For ground-based astronomy, the co-addition of adaptive optics again increases angular resolution up to providing diffraction-limited imaging at least in the infrared. Active and adaptive optics marked milestone progress in the detection of exoplanets, super-massive black holes, and large-scale structure of galaxies. This paper is dedicated to highly deformable active optics that can generate non-axisymmetric aspheric surfaces – or freeform surfaces – by use of a minimum number of actuators: a single uniform load acts over the surface of a vase-form substrate whilst under reaction to its elliptical perimeter ring. Two such instruments are presented: (1) the Faint Intergalactic Redshifted Emission Balloon (FIREBall) telescope and multi object spectrograph (MOS) where the freeform reflective diffraction grating is generated by replication of a deformable master grating, and (2) the MESSIER wide-field low-central-obstruction three-mirror-anastigmat (TMA) telescope proposal where the freeform mirror is generated by stress figuring and elastic relaxation. Freeform surfaces were obtained by plane super-polishing. Preliminary analysis required use of the optics theory of 3rd-order aberrations and elasticity theory of thin elliptical plates. Final cross-optimizations were carried out with Zemax raytracing code and Nastran FEA elasticity code in order to determine geometry of the deformable substrates.


2012 ◽  
Vol 29 (7) ◽  
pp. 1359 ◽  
Author(s):  
Pietro Schipani ◽  
Lothar Noethe ◽  
Carmelo Arcidiacono ◽  
Javier Argomedo ◽  
Massimo Dall’Ora ◽  
...  
Keyword(s):  

2002 ◽  
Author(s):  
Roberto F. Viotti ◽  
Cesare D. La Padula ◽  
Agostino Vignato ◽  
Gerard R. Lemaitre ◽  
Pierre Montiel ◽  
...  

2004 ◽  
Author(s):  
Gerard R. Lemaitre ◽  
Pierre Montiel ◽  
Patrice Joulie ◽  
Kjetil Dohlen ◽  
Patrick Lanzoni

2014 ◽  
Author(s):  
R. Holzlöhner ◽  
A. Rakich ◽  
L. Noethe ◽  
K. Kuijken ◽  
P. Schipani

2018 ◽  
Vol 24 (1) ◽  
pp. 2 ◽  
Author(s):  
Gerard Lemaitre ◽  
Pascal Vola ◽  
Eduard Muslimov

Active optics techniques in astronomy provide high imaging quality. This paper is dedicated to highly deformable active optics that can generate non-axisymmetric aspheric surfaces—or freeform surfaces—by use of a minimum number of actuators. The aspheric mirror is obtained from a single uniform load that acts over the surface of a closed-form substrate whilst under axial reaction to its elliptical perimeter ring during spherical polishing. MESSIER space proposal is a wide-field low-central-obstruction folded-two-mirror-anastigmat or here called briefly three-mirror-anastigmat (TMA) telescope. The optical design is a folded reflective Schmidt. Basic telescope features are 36 cm aperture, f/2.5, with 1.6° × 2.6° field of view and a curved field detector allowing null distortion aberration for drift-scan observations. The freeform mirror is generated by spherical stress polishing that provides super-polished freeform surfaces after elastic relaxation. Preliminary analysis required use of the optics theory of 3rd-order aberrations and elasticity theory of thin elliptical plates. Final cross-optimizations were carried out with Zemax raytracing code and Nastran FEA elasticity code in order to determine the complete geometry of a glass ceramic Zerodur deformable substrate.


Author(s):  
M. G. Lagally

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.


2013 ◽  
Vol 183 (8) ◽  
pp. 888-894
Author(s):  
G.M. Beskin ◽  
S.V. Karpov ◽  
V.L. Plokhotnichenko ◽  
S.F. Bondar ◽  
A.V. Perkov ◽  
...  

2010 ◽  
Vol 180 (4) ◽  
pp. 424 ◽  
Author(s):  
G.M. Beskin ◽  
S.V. Karpov ◽  
S.F. Bondar ◽  
V.L. Plokhotnichenko ◽  
A. Guarnieri ◽  
...  

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