Optical glass: standards – present state and outlook

2015 ◽  
Vol 4 (5-6) ◽  
Author(s):  
Peter Hartmann
Keyword(s):  
Water Resistance ◽  
Optical Glass ◽  
Optical Element ◽  
International Organization ◽  
Optical Elements ◽  
Glass Quality ◽  
Element Size ◽  
Backward Compatibility ◽  
Cover Material ◽  
Selection Of

AbstractIn 1996, the international organization for standardization ISO started the standards series ISO 10110 specifying indications in drawings of optical elements. Three parts cover material properties: part 2 (stress birefringence), 3 (bubbles and inclusions), and 4 (inhomogeneity and striae). Customers used to just send optical element drawings to glass manufacturers often leading to uncertainty, overspecification, and delivery problems. The raw glass standard ISO 12123 of 2010 allows direct addressing of raw glass specifications. Harmonizing ISO 10110 with ISO 12123 and progress in inspection methods require updating of the material specifying parts. A new part 18 containing all properties is under preparation and is meant to replace parts 2–4. ISO 12123 will be amended by introducing definitions for relative partial dispersions and reference normal lines and grade denominations for tolerance ranges. The working draft ISO/WD 10110 part 18 extends indication possibilities to allow relating to ISO 12123 while ensuring backward compatibility. Default optical glass quality and direct specification of raw glass simplify tolerancing considerably. Annexes support selection of appropriate quality classes referring to optical element size categories. Test and inspection standards on chemical resistances, hardness, stress birefringence, and optical homogeneity will be maintained. Standards for water resistance, refractive index, and striae inspection are being prepared.

scholarly journals Nanooptical elements for visual verification

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Goncharsky ◽  
Anton Goncharsky ◽  
Dmitry Melnik ◽  
Svyatoslav Durlevich
Keyword(s):  
Electron Beam ◽  
Electron Beam Lithography ◽  
Mass Production ◽  
Optical Element ◽  
Visual Image ◽  
Zero Order ◽  
Diffractive Optical Elements ◽  
Optical Elements ◽  
Standard Equipment ◽  
Diffractive Element

AbstractThis paper focuses on the development of flat diffractive optical elements (DOEs) for protecting banknotes, documents, plastic cards, and securities against counterfeiting. A DOE is a flat diffractive element whose microrelief, when illuminated by white light, forms a visual image consisting of several symbols (digits or letters), which move across the optical element when tilted. The images formed by these elements are asymmetric with respect to the zero order. To form these images, the microrelief of a DOE must itself be asymmetric. The microrelief has a depth of ~ 0.3 microns and is shaped with an accuracy of ~ 10–15 nm using electron-beam lithography. The DOEs developed in this work are securely protected against counterfeiting and can be replicated hundreds of millions of times using standard equipment meant for the mass production of relief holograms.

scholarly journals Arbitrary polarization conversion for pure vortex generation with a single metasurface

Nanophotonics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 727-732
Author(s):  
Marco Piccardo ◽  
Antonio Ambrosio
Keyword(s):  
Angular Momentum ◽  
Polarization Conversion ◽  
Vortex Beam ◽  
Vortex Generation ◽  
Optical Elements ◽  
Amplitude Control ◽  
Cavity Resonators ◽  
Vortex Beams ◽  
Topological Charges ◽  
Selection Of

AbstractThe purity of an optical vortex beam depends on the spread of its energy among different azimuthal and radial modes, also known as $\ell $- and p-modes. The smaller the spread, the higher the vortex purity and more efficient its creation and detection. There are several methods to generate vortex beams with well-defined orbital angular momentum, but only few exist allowing selection of a pure radial mode. These typically consist of many optical elements with rather complex arrangements, including active cavity resonators. Here, we show that it is possible to generate pure vortex beams using a single metasurface plate—called p-plate as it controls radial modes—in combination with a polarizer. We generalize an existing theory of independent phase and amplitude control with birefringent nanopillars considering arbitrary input polarization states. The high purity, sizeable creation efficiency, and impassable compactness make the presented approach a powerful complex amplitude modulation tool for pure vortex generation, even in the case of large topological charges.

Complex optical elements for scanning helium microscopy through 3D printing

2021 ◽  
Author(s):  
Matthew Bergin ◽  
Thomas Myles ◽  
Aleksandar Radić ◽  
Christopher Hatchwell ◽  
Sam Lambrick ◽  
...  
Keyword(s):  
3D Printing ◽  
Multiple Scattering ◽  
Low Cost ◽  
Optical Element ◽  
Next Generation ◽  
Background Signal ◽  
Optical Elements ◽  
Cost Components

Abstract Developing the next generation of scanning helium microscopes requires the fabrication of optical elements with complex internal geometries. We show that resin stereolithography (SLA) 3D printing produces low-cost components with the requisite convoluted structures whilst achieving the required vacuum properties, even without in situ baking. As a case study, a redesigned pinhole plate optical element of an existing scanning helium microscope was fabricated using SLA 3D printing. In comparison to the original machined component, the new optical element minimised the key sources of background signal, in particular multiple scattering and the secondary effusive beam.

A simple optical system delivering a tunable micrometer pink beam that can compensate for heat-induced deformations

2015 ◽  
Vol 22 (4) ◽  
pp. 930-935 ◽  
Author(s):  
Ruben Reininger ◽  
Zunping Liu ◽  
Gilles Doumy ◽  
Linda Young
Keyword(s):  
Optical System ◽  
Heat Load ◽  
Optical Element ◽  
High Energy ◽  
Angle Of Incidence ◽  
Optical Elements ◽  
Source Distance ◽  
Energy Cutoff ◽  
Working Distance ◽  
Photon Source

The radiation from an undulator reflected from one or more optical elements (usually termed `pink-beam') is used in photon-hungry experiments. The optical elements serve as a high-energy cutoff and for focusing purposes. One of the issues with this configuration is maintaining the focal spot dimension as the energy of the undulator is varied, since this changes the heat load absorbed by the first optical element. Finite-element analyses of the power absorbed by a side water-cooled mirror exposed to the radiation emitted by an undulator at the Advanced Photon Source (APS) and at the APS after the proposed upgrade (APSU) reveals that the mirror deformation is very close to a convex cylinder creating a virtual source closer to the mirror than the undulator source. Here a simple optical system is described based on a Kirkpatrick–Baez pair which keeps the focus size to less than 2 µm (in the APSU case) with a working distance of 350 mm despite the heat-load-induced change in source distance. Detailed ray tracings at several photon energies for both the APS and APSU show that slightly decreasing the angle of incidence on the mirrors corrects the change in the `virtual' position of the source. The system delivers more than 70% of the first undulator harmonic with very low higher-orders contamination for energies between 5 and 10 keV.

scholarly journals EVALUATION OF CONTRACTORS BY USING COPRAS - THE MULTIPLE CRITERIA METHOD

2005 ◽  
Vol 11 (3) ◽  
pp. 158-169 ◽  
Author(s):  
Algirdas Andruškevičius
Keyword(s):  
Evaluation Criteria ◽  
Multiple Criteria ◽  
International Organization ◽  
Point Scale ◽  
Multicriteria Decision ◽  
Decision Method ◽  
Selection Of

Some methods allowing for the selection of the most suitable contractor based on 26 criteria are offered. The bidding procedures of FIDIC, the international organization of consulting engineers are assessed. Contractors are evaluated by a multicriteria decision method COPRAS. The significance of the contractor evaluation criteria is determined by ranking. A description of the criteria and their rankings according to 100‐point scale are provided. A case study of selecting the contractor for the construction of a trade and entertainment centre out often bidders is also described.

scholarly journals On a problem of the synthesis of binary nano-optical elements

2016 ◽  
pp. 415-424
Author(s):  
А.А. Гончарский ◽  
С.Ю. Серёжников
Keyword(s):  
Electron Beam ◽  
Augmented Reality ◽  
Electron Beam Lithography ◽  
Optical Element ◽  
Diffractive Optical Elements ◽  
Partial Loss ◽  
Optical Elements ◽  
Optical Images ◽  
Augmented Reality Technology ◽  
Security Label

В рамках широко распространенной технологии Augmented Reality обсуждается возможность контроля подлинности защитных оптических меток на основе бинарных нанооптических элементов. С помощью смартфона фотографируют изображение защитной метки. Полученное изображение интерпретируется как дифракционный оптический элемент. В приближении Френеля рассчитывают изображение, формируемое дифракционным оптическим элементом, которое используют для идентификации подлинности защитной метки. Защитная метка представляет собой фазовый оптический элемент, глубина микрорельефа которого не превышает 0.5 мкм. Нанооптические элементы изготавливаются с помощью электроннолучевой литографии. Разработанные нанооптические элементы устойчивы к частичному повреждению микрорельефа и могут быть использованы для идентификации банкнот, документов и др. This paper deals with optical security label identification technology as a part of augmented reality technology. Security labels are based on binary nanooptical elements and are photographed using a smartphone. Photographed images are interpreted as diffractive optical elements. Optical images formed by these diffractive elements are computed using the Fresnel approximation. These images are used to identify the security labels. A security label consists of a phase optical element whose microrelief height is of no more than 0.5 $\mu$m. Nanooptical elements are manufactured using electron-beam lithography. The optical security labels are resistant against microrelief damages and can withstand partial loss of an image. The optical elements developed can be used to protect and identify banknotes, documents, etc.

scholarly journals CALCULATION OF THE ACHROMATIC DIFFRACTION SYSTEM WITH CORRECTED SPHERICAL ABERRATION (part 2)

2020 ◽  
Vol 8 (1) ◽  
pp. 127-133
Author(s):  
Yury Ts. Batomunkuev ◽  
Alexandra A. Pechenkina
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Optical Element ◽  
Diffraction Order ◽  
Image Plane ◽  
Chromatic Aberration ◽  
Real Image ◽  
Optical Elements ◽  
A Value ◽  
Analytical Expressions

Achromatization of a three-component diffraction system consisting of one thick and two thin hologram optical elements is considered in the work. Analytical expressions are obtained for correcting the chromatic aberration of the position of a thick focusing hologram optical element by two scattering thin hologram optical elements in a given spectrum range. It is shown that achromatization is achieved for such a three-component system using two thin hologram elements located symmetrically on both sides of the thick element and having a value of the working diffraction order greater than the ratio of the focal length to the distance from the thin element to the image plane (at a given wavelength). The proposed three-component holographic system can be used to convert both an imaginary image into a real image and a real into an imaginary image in predetermined spectral regions of the visible, ultraviolet or infrared ranges of the spectrum.

scholarly journals Modern Types of Axicons: New Functions and Applications

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6690
Author(s):  
Svetlana N. Khonina ◽  
Nikolay L. Kazanskiy ◽  
Pavel A. Khorin ◽  
Muhammad A. Butt
Keyword(s):  
Intensity Distribution ◽  
Integrated Circuit ◽  
Bessel Beam ◽  
Optical Element ◽  
Spatial Light Modulators ◽  
Optical Antennas ◽  
Optical Elements ◽  
Photonic Integrated Circuit ◽  
Light Modulators

Axicon is a versatile optical element for forming a zero-order Bessel beam, including high-power laser radiation schemes. Nevertheless, it has drawbacks such as the produced beam’s parameters being dependent on a particular element, the output beam’s intensity distribution being dependent on the quality of element manufacturing, and uneven axial intensity distribution. To address these issues, extensive research has been undertaken to develop nondiffracting beams using a variety of advanced techniques. We looked at four different and special approaches for creating nondiffracting beams in this article. Diffractive axicons, meta-axicons-flat optics, spatial light modulators, and photonic integrated circuit-based axicons are among these approaches. Lately, there has been noteworthy curiosity in reducing the thickness and weight of axicons by exploiting diffraction. Meta-axicons, which are ultrathin flat optical elements made up of metasurfaces built up of arrays of subwavelength optical antennas, are one way to address such needs. In addition, when compared to their traditional refractive and diffractive equivalents, meta-axicons have a number of distinguishing advantages, including aberration correction, active tunability, and semi-transparency. This paper is not intended to be a critique of any method. We have outlined the most recent advancements in this field and let readers determine which approach best meets their needs based on the ease of fabrication and utilization. Moreover, one section is devoted to applications of axicons utilized as sensors of optical properties of devices and elements as well as singular beams states and wavefront features.

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