scholarly journals Effective Optical System Assembly Using Ultra-Precise Manufactured References

2020 ◽  
Vol 14 (4) ◽  
pp. 644-653
Author(s):  
Andreas Gebhardt ◽  
Matthias Beier ◽  
Erik Schmidt ◽  
Thomas Rendel ◽  
Ute Gawronski ◽  
...  
Keyword(s):  
Optical System ◽  
Laser Diodes ◽  
Optical Component ◽  
Machining Process ◽  
Optical Systems ◽  
Active Components ◽  
High Quality ◽  
Diamond Machining ◽  
Position And Orientation ◽  
Aspherical Lenses

The present work demonstrates that exactly manufactured references for joining, mounting, and metrology purposes are crucial in the effective assembly of high-quality optical systems. Based on the alignment turning of spherical and aspherical lenses, the proposed approach can be transferred to non-rotational symmetric elements such as prisms, active components (e.g., laser diodes), and freeform mirrors. The complexity of the optical component decides whether on-machine metrology or specific measurement setups need to be used to determine the position and orientation of the references with respect to the optical function. The resulting correction data are considered during the machining process. The subsequent correction cycle realizes mounting and metrology references down to sub-micron precision using diamond-machining techniques. This approach facilitates the assembly of demanding optical systems and even freeform arrangements in a predictable and passive manner. Different machining setups as well as the corresponding metrology approaches are demonstrated, and results are presented for representative components. The effectiveness of the approach is discussed using rotationally symmetrical lens systems and a snap-together freeform mirror system.

Modular Concepts in the Design of Electron Optical Systems

1970 ◽  
Vol 28 ◽  
pp. 362-363
Author(s):  
J.R. Fairbanks
Keyword(s):  
Optical System ◽  
Practical Approach ◽  
Optical Systems ◽  
Objective Lens ◽  
Scientific Instruments ◽  
High Quality ◽  
Condenser Lens ◽  
The Third ◽  
Instrument Maker ◽  
Electron Microscopes

A practical approach to the design of complex machinery is to standardize parts as much as possible. This approach is equally valid for the design of scientific instruments such as electron microscopes, provided there is no sacrifice in performance for the completed instrument. As an example, the illustration shows modular parts used elsewhere in an electron optical column, which are organized by design in this particular case to perform as a second condenser lens.Consider the upper polepiece. This modular piece is used in nine other places in the column; once in the lower condenser as shown, twice in the upper condenser, twice in the objective lens, twice in the second projector, twice in the third projector, and once in the first projector. Since all the polepieces are identical, they are all of the highest quality needed in the most critical lens, the objective. The optical system thus benefits from standardized high quality lenses, (which ultimately is the user's benefit), and the instrument maker benefits from the economy of making pieces in replicate.

Atomic Resolution in Crystal Aperture Stem

1990 ◽  
Vol 48 (1) ◽  
pp. 236-237
Author(s):  
J T Fourie
Keyword(s):  
Optical System ◽  
Spherical Aberration ◽  
Three Dimensional ◽  
Transmission Function ◽  
Optical Systems ◽  
Bragg Angle ◽  
Electron Optical System ◽  
Intimate Contact ◽  
Diffraction Effects ◽  
Design Aspect

The attempts at improvement of electron optical systems to date, have largely been directed towards the design aspect of magnetic lenses and towards the establishment of ideal lens combinations. In the present work the emphasis has been placed on the utilization of a unique three-dimensional crystal objective aperture within a standard electron optical system with the aim to reduce the spherical aberration without introducing diffraction effects. A brief summary of this work together with a description of results obtained recently, will be given.The concept of utilizing a crystal as aperture in an electron optical system was introduced by Fourie who employed a {111} crystal foil as a collector aperture, by mounting the sample directly on top of the foil and in intimate contact with the foil. In the present work the sample was mounted on the bottom of the foil so that the crystal would function as an objective or probe forming aperture. The transmission function of such a crystal aperture depends on the thickness, t, and the orientation of the foil. The expression for calculating the transmission function was derived by Hashimoto, Howie and Whelan on the basis of the electron equivalent of the Borrmann anomalous absorption effect in crystals. In Fig. 1 the functions for a g220 diffraction vector and t = 0.53 and 1.0 μm are shown. Here n= Θ‒ΘB, where Θ is the angle between the incident ray and the (hkl) planes, and ΘB is the Bragg angle.

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.

scholarly journals A Method to Generate Vector Beams with Adjustable Amplitude in the Focal Plane

2020 ◽  
Vol 10 (7) ◽  
pp. 2313 ◽  
Author(s):  
Alexandru Crăciun ◽  
Traian Dascălu
Keyword(s):  
Optical System ◽  
Focal Plane ◽  
Focal Point ◽  
Polarization State ◽  
Optical Component ◽  
Stimulated Emission ◽  
Matrix Formalism ◽  
Sted Microscopy ◽  
Diffraction Integral ◽  
Vector Beams

We design and investigate an original optical component made of a c-cut uniaxial crystal and an optical system to generate cylindrical vector beams with an adjustable polarization state. The original optical component has a specific, nearly conical shape which allows it to operate like a broadband wave retarder with the fast axis oriented radially with respect to the optical axis. We show via numerical simulations, using the Debye–Wolf diffraction integral, that the focal spot changes depending on the polarization state, thus enabling the control of the focal shape. Non-symmetrical shapes can be created although the optical system and incoming beam are circularly symmetric. We explained, using Jones matrix formalism, that this phenomenon is connected with the Gouy phase difference acquired by certain modes composing the beam due to propagation to the focal plane. We present our conclusions in the context of two potential applications, namely, stimulated emission depletion (STED) microscopy and laser micromachining. The optical system can potentially be used for STED microscopy for better control of the point-spread function of the microscope and to decrease the unwanted light emitted from the surroundings of the focal point. We give an analytical expression for the shape of the original component using the aspherical lens formula for the two versions of the component: one for each potential application.

High-quality cutting edge preparation of micromilling tools using wet abrasive jet machining process

2017 ◽  
Vol 12 (1) ◽  
pp. 45-51 ◽  
Author(s):  
E. Krebs ◽  
M. Wolf ◽  
D. Biermann ◽  
W. Tillmann ◽  
D. Stangier
Keyword(s):  
Cutting Edge ◽  
Machining Process ◽  
High Quality ◽  
Abrasive Jet Machining ◽  
Cutting Edge Preparation ◽  
Edge Preparation

Image Distortion, between Unwanted Geometric Aberration and the Tool Used to Improve Observation Equipment Performance

2014 ◽  
Vol 555 ◽  
pp. 751-758 ◽  
Author(s):  
Nicolae Guzulescu ◽  
Cornel Todirică ◽  
Daniel Lăpădat
Keyword(s):  
Optical System ◽  
Measurement Errors ◽  
Optical Measurement ◽  
Image Distortion ◽  
Field Of View ◽  
Optical Systems ◽  
Object Appearance ◽  
And Control ◽  
Measurement And Control ◽  
Equipment Performance

An distortion aberration free optical system forms an orthoscopic image mean that is similar to original object, undeformed. Naturally imply that most optical systems are designed so that the image distortion is minimal, not to cause inconvenience to the user about either the object appearance – when it comes to a camera or camcorder, or the deformities that may cause measurement errors – when it comes to optical measurement and control equipment. However there are situations when distortion is desired to improve some performances of the observation optical system. In this article we present how distortion is used to increase the field of view, and also how distortion is used to optimize the field of view – resolution compromise.

The Microstructure of Nanocarrier System and its Application in Cosmetics

Nano LIFE ◽  
2020 ◽  
Vol 10 (04) ◽  
pp. 2040012 ◽  
Author(s):  
Liang Gan ◽  
Jianjun Deng ◽  
Liuyun Hu ◽  
Wangwang Lu ◽  
Dingyuan Cui ◽  
...  
Keyword(s):  
Pharmacological Activity ◽  
Targeted Delivery ◽  
Nanostructured Lipid Carriers ◽  
Living Standard ◽  
Intracellular Uptake ◽  
Sustained Delivery ◽  
Micro Structure ◽  
Active Components ◽  
High Quality ◽  
Active Molecule

With the improvement of living standard, consumers have higher requirements on functions of cosmetics. Nanocarrier systems can offer remarkable features and have potential in targeted-oriented active molecule delivery. In order to improve the functions of cosmetics, nanocarrier system has been widely used in cosmetics. Nanoemulsions, liposomes and nanostructured lipid carriers (NLCs) have attracted considerable attention as three main nanocarrier systems for cosmetics and personal care products. They have a lot of advantages such as improving stability, improving tissue macrophages distribution, increasing solubility, bioavailability, protection of actives from toxicity, enhancing pharmacological activity and intracellular uptake, targeted delivery and sustained delivery. In this paper, the definition, classification and micro-structure of these three carriers were reviewed. The applications of nanoemulsions, liposomes and NLCs in cosmetics were discussed. The beneficial aspects of nanoemulsions, liposomes and NLCs in cosmetics are very broad. They have very promising future for the delivery of cosmetic active components/ingredients and for the production of high-quality cosmetics.

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