scholarly journals Design and Experimental Implementation of a Multi-Cloak Paraxial Optical System

Photonics ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 358
Author(s):  
Alicia Fresno-Hernández ◽  
Braulio García-Cámara ◽  
Juan Carlos Torres ◽  
José Manuel Sánchez-Pena
Keyword(s):  
Visual Field ◽  
Optical System ◽  
Mathematical Formalism ◽  
Transformation Optics ◽  
Lens System ◽  
Successful Operation ◽  
Naked Eye ◽  
Experimental Implementation ◽  
Simple Arrangement ◽  
Simple Systems

Electromagnetic cloaking has being continuously pursued using a large variety of approaches. In recent years, this effect has been observed using either complex devices based on the so-called Transformation Optics or simple systems based on conventional optics with proper characteristics. In the latter case, a simple arrangement of lenses working in the paraxial regime can provide broadband visible cloaking in a wide area. In this work, we analyzed and generalized this method by proposing a five-lens system producing at least three potential invisible regions with a large cloaked area (>90% of the visual field). In particular, we developed the mathematical formalism and show, both numerically and experimentally, the successful operation of the cloaking system with the naked eye.

scholarly journals Spatiotemporal multiplexing method for visual field of view extension in holographic displays with naked eye observation

2016 ◽  
Vol 24 (3) ◽  
Author(s):  
G. Finke ◽  
M. Kujawińska ◽  
T. Kozacki ◽  
W. Zaperty
Keyword(s):  
Visual Field ◽  
Optical System ◽  
Wigner Distribution ◽  
Field Of View ◽  
Distribution Analysis ◽  
Holographic Display ◽  
Holographic Imaging ◽  
Naked Eye ◽  
Holographic Displays ◽  
Functional Problems

AbstractIn this paper we propose a method which allows to overcome the basic functional problems in holographic displays with naked eye observation caused by delivering too small images visible in narrow viewing angles. The solution is based on combining the spatiotemporal multiplexing method with a 4f optical system. It enables to increase an aperture of a holographic display and extend the angular visual field of view. The applicability of the modified display is evidenced by Wigner distribution analysis of holographic imaging with spatiotemporal multiplexing method and by the experiments performed at the display demonstrator.

A NEW METHOD OF LENS CENTERING IN THE OPTICAL SYSTEM BY USING SPECIAL MOUNT

2021 ◽  
pp. 137-144
Author(s):  
Bao Bui Dinh
Keyword(s):  
Optical System ◽  
Optical Axis ◽  
Assembly Process ◽  
Optical Surface ◽  
Lens System ◽  
High Quality ◽  
Manufacturing Equipment ◽  
Influence Coefficients ◽  
Process Solutions

Decentration in lens systems (for example objectives) significantly degrades the quality of image, such as the coma. In order to reduce lens decentration, the lenses are centered while manufacturing, while gluing, while attachment in the mounts. Significant decrease in the lenses decentering in the mounts is achieved by using a special manufacturing equipment, which allow combining the optical axis of the lens with the base axis of the mount in assembly process. Solutions for coma's alignment by shifting, tilting and rotation their components are also provided in the construction of high-quality objectives (microscopes [1-7], photolithographic, aerophotographic). For optimization of methods for such adjustment the influence coefficients of decentering of each optical surface of the lens system on the value and sign of coma must be calculated and taken into account. In this paper, we propose a special mounting which combined with the Opticentric of Trioptics device to center the lenses. The results show that the decentering is significantly reduced (0.9µm) compared to (44.2µm) with using a reference mount.

Applied Research on the Electric Wet Effect in Optical System Design

2011 ◽  
Vol 383-390 ◽  
pp. 4889-4894
Author(s):  
Zhi Qin Huang ◽  
Pei Ying Quan ◽  
Jin Li Zhang
Keyword(s):  
Optical System ◽  
Zoom Lens ◽  
Lens System ◽  
Optical Lens ◽  
The Past ◽  
Vision Correction ◽  
Past Half Century ◽  
Great Progress ◽  
Mechanical Movement ◽  
Past Half

In the past half century, the camera industry has developed very rapidly, which drove the optical lens and optical zoom technology to make great progress. The zoom lens’ technology principle of current mainstream optical zoom lens system is achieved by adjusting the relative position of the lens, objects and the focus. This paper takes the double-liquid zoom lens based on electric wet effect as the basis , the new zoom optical system is designed to achieve motor control without mechanical movement, then the vision correction is designed by using liquid lens, such as the correction of myopia and hyperopia, which can automatically identify the eyes degrees of myopia and hyperopia, avoid frequent replacement lens steps when optometry is done for eyes.

scholarly journals Astrometric Characteristics of the Abastumani Astrophysical Observatory 125 cm Reflector (AZT-11) of Ritchey-Cretien Optical System

1986 ◽  
Vol 109 ◽  
pp. 289-292
Author(s):  
G. N. Salukvadze
Keyword(s):  
Optical System ◽  
Lens System ◽  
Multiple Systems

Quite a number of instances are known when Schmidt, mirror-lens system telescopes and generally reflectors are used for solving the problems of photographic astrometry.This paper describes the use of the Ritchey-Cretien telescope (AZT-11) at the Abastumani Astrophysical Observatory for determining relative positions of the members of multiple systems.

Ultraviolet-Fluorescence Bronchoscopy in Early Detection of Bronchogenic Carcinoma

1978 ◽  
Vol 87 (4) ◽  
pp. 528-532 ◽  
Author(s):  
Dietrich Hürzeler
Keyword(s):  
Early Detection ◽  
Optical System ◽  
Bronchogenic Carcinoma ◽  
Uv Light ◽  
Naked Eye ◽  
Ciliary Action ◽  
Malignant Changes ◽  
Normal Mucous Membrane ◽  
Superficial Tumor ◽  
Detailed Diagnosis

The still unsatisfactory prognosis of bronchogenic carcinoma prompted the search for possibilities of better early and detailed diagnosis. This led us to the idea of UV-fluorescence bronchoscopy. The patient inhales 5 ml of an aqueous 5% solution of fluorescein, together with a β2 stimulator, 10–15 minutes before the bronchoscopy, by means of a pressure inhaler. While the normal mucous membrane cleanses itself by virtue of ciliary action (secretions containing fluorescein are expectorated or drawn off during the bronchoscopy), carcinoma, carcinomatous lymphangiosis, superficial tumor infiltrations and nonciliated metaplasias are stained. These places fluoresce in UV light, even when they cannot be observed with the naked eye or with an optical system. In this way, they are made visible for directed biopsy. Malignant changes not discernible by means of the methods hitherto employed can thus be diagnosed and sites determined with greater accuracy for proposed resection.

scholarly journals A generalized theory of the transition time for sequential enzyme reactions

1981 ◽  
Vol 199 (1) ◽  
pp. 155-161 ◽  
Author(s):  
J S Easterby
Keyword(s):  
Steady State ◽  
Enzyme Concentration ◽  
Transition Time ◽  
Successful Operation ◽  
Enzyme Reactions ◽  
Minimum Requirements ◽  
Lag Period ◽  
State Production ◽  
Definition Of ◽  
Simple Systems

In a sequence of coupled enzyme reactions the steady-state production of product is preceded by a lag period or transition time during which the intermediates of the sequence are accumulating. Provided that a steady state is eventually reached, the magnitude of this lag may be calculated, even when the differentiation equations describing the process have no analytical solution. The calculation may be made for simple systems in which the enzymes obey Michaelis-Menten kinetics or for more complex pathways in which intermediates act as modifiers of the enzymes. The transition time associated with each intermediate in the sequence is given by the ratio of the appropriate steady-state intermediate concentration to the steady-state flux. The theory is also applicable to the transition between steady states produced by flux changes. Application of the theory to coupled enzyme assays allows a definition of the minimum requirements for successful operation of the assay. The theory can be extended to deal with sequences in which the enzyme concentration exceeds substrate concentration.

Introduction

1978 ◽  
Vol 36 (3) ◽  
pp. 543-544
Author(s):  
W. Bernard
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Gene Mapping ◽  
Molecular Genetics ◽  
Cell Biology ◽  
Gene Activity ◽  
Close Connection ◽  
Basic Information ◽  
Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

A Field Emission System For Transmission Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 298-299
Author(s):  
Michel Troyonal ◽  
Huei Pei Kuoal ◽  
Benjamin M. Siegelal
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Optical System ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Objective Lens ◽  
Electron Optical System ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Emission System

A field emission system for our experimental ultra high vacuum electron microscope has been designed, constructed and tested. The electron optical system is based on the prototype whose performance has already been reported. A cross-sectional schematic illustrating the field emission source, preaccelerator lens and accelerator is given in Fig. 1. This field emission system is designed to be used with an electron microscope operated at 100-150kV in the conventional transmission mode. The electron optical system used to control the imaging of the field emission beam on the specimen consists of a weak condenser lens and the pre-field of a strong objective lens. The pre-accelerator lens is an einzel lens and is operated together with the accelerator in the constant angular magnification mode (CAM).

Interpretation of irradiation-induced changes in electron diffractograms and images of extinction contours at low temperatures

1984 ◽  
Vol 42 ◽  
pp. 268-269
Author(s):  
E. Knapek ◽  
H. Formanek ◽  
G. Lefranc ◽  
I. Dietrich
Keyword(s):  
Low Temperatures ◽  
Carbon Films ◽  
Organic Crystals ◽  
Wide Spread ◽  
Lens System ◽  
Preparation Conditions ◽  
Thin Carbon ◽  
Electron Diffractograms ◽  
Diffraction Patterns ◽  
Induced Changes

A few years ago results on cryoprotection of L-valine were reported, where the values of the critical fluence De i.e, the electron exposure which decreases the intensity of the diffraction reflections by a factor e, amounted to the order of 2000 + 1000 e/nm2. In the meantime a discrepancy arose, since several groups published De values between 100 e/nm2 and 1200 e/nm2 /1 - 4/. This disagreement and particularly the wide spread of the results induced us to investigate more thoroughly the behaviour of organic crystals at very low temperatures during electron irradiation.For this purpose large L-valine crystals with homogenuous thickness were deposited on holey carbon films, thin carbon films or Au-coated holey carbon films. These specimens were cooled down to nearly liquid helium temperature in an electron microscope with a superconducting lens system and irradiated with 200 keU-electrons. The progress of radiation damage under different preparation conditions has been observed with series of electron diffraction patterns and direct images of extinction contours.

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