Design and Development of an Automated Dual-Mode Microscopic System Using Electrically Tunable Lenses

2021 ◽  
pp. 1-12
Author(s):  
Neelam Barak ◽  
Vineeta Kumari ◽  
Gyanendra Sheoran
Keyword(s):  
Focal Depth ◽  
Numerical Aperture ◽  
Image Plane ◽  
Image Resolution ◽  
Proof Of Concept ◽  
Dual Mode ◽  
Modes Of Operation ◽  
Viable Solution ◽  
Difficult Challenge ◽  
Tunable Lenses

Maintaining telecentricity and zooming in microscopic systems with prolonged depths of focus is a difficult challenge because these properties degrade while moving to different axial planes in the extended focal depth. In this paper, we propose the proof of concept for an automated dual-mode microscopic system that combines two electrically tunable lenses (ETLs) with a variable numerical aperture controller placed. It acts as a viable solution to allow both multiplane microscopic zooming and telecentricity with consistent image resolution throughout the objective's extended focal depth. The image plane remains fixed for both the modes of operation, namely telecentricity and multiplane zooming. To validate the performance of the proposed idea, both simulations and experiments are carried out at various ETL curvature ranges. Over the whole zoom distance range, the experimental zoom ratio is determined to range from −2.723X to −34.42X. The experimental and simulation findings are compared and found to be quite similar, with magnification error percentages of 2.26% for zoom mode and 1.27% for telecentric mode. The comprehensive explanation of simulation and experimental results demonstrate the feasibility of the proposed method for both multiplane zoom and telecentric operations on a single platform in microscopic applications.

scholarly journals DEEP FOCUS; A DIGITAL IMAGE PROCESSING TECHNIQUE TO PRODUCE IMPROVED FOCAL DEPTH IN LIGHT MICROSCOPY

2011 ◽  
Vol 19 (3) ◽  
pp. 163 ◽  
Author(s):  
Noel T Goldsmith
Keyword(s):  
Light Microscopy ◽  
Digital Image ◽  
Computer Control ◽  
Focal Depth ◽  
Numerical Aperture ◽  
Depth Resolution ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Composite Image ◽  
Deep Focus

In light microscopy, the spatial transverse resolution is a function of the wavelength and numerical aperture. The depth resolution is another function of these parameters. The factors that enable the detection of fine detail, make the sharp focusing of more than a thin slice of the depth in an object impossible. When the examination of fracture surfaces is attempted using light reflection microscopy, the roughness will often restrict the in-focus parts of an image to a small portion of the field of view. Several authors have presented methods that enable a set of digitised images to be processed into a single composite image which contains the in-focus parts from each image. These methods are effective, unfortunately the noise present in each digital image is accumulated, resulting in increasingly noisy composite images as the number of images in a set is increased. During processing, a separate image depicting the heights in the surface, i.e. a contour map, may be produced. This image is the key that enables the production of an in focus composite image which does not accumulate noise. Image analysis under computer control will frequently require the use of automatic focusing. Several authors have published criteria which may be used to determine the state of focus of an image. Such criteria have a clear application to the above process. This paper presents an evaluation of some methods used for the processing of such images, and also some procedures used for the determination of sharpness of focus and demonstrates a sensitive method for the evaluation of such procedures. Finally, an implementation of a method which uses the one of the simplest focus criteria is presented, and a procedure for the production of deep focus images which are free from the accumulation of noise.

scholarly journals Compact diffractive optics for THz imaging

2018 ◽  
Vol 58 (1) ◽  
Author(s):  
Linas Minkevičius ◽  
Simonas Indrišiūnas ◽  
Ramūnas Šniaukas ◽  
Gediminas Račiukaitis ◽  
Vytautas Janonis ◽  
...  
Keyword(s):  
Spherical Surface ◽  
Focal Depth ◽  
Numerical Aperture ◽  
Picosecond Laser ◽  
Fresnel Lens ◽  
Diffractive Optics ◽  
Direct Writing ◽  
Thz Imaging ◽  
Beam Focusing ◽  
Phase Quantization

We present a compact diffractive silicon-based multilevel phase Fresnel lens (MPFL) with up to 50 mm in diameter and a numerical aperture up to 0.86 designed and fabricated for compact terahertz (THz) imaging systems. The laser direct writing technology based on a picosecond laser was used to fabricate diffractive optics on silicon with a different number of phase quantization levels P reaching an almost kinoform spherical surface needed for efficient THz beam focusing. Focusing performance was investigated by measuring Gaussian beam intensity distribution in the focal plane and along the optical axis of the lens. The beam waist and the focal depth for each MPFL were evaluated. The influence of the phase quantization number on the focused beam amplitude was estimated, and the power transmission efficiency reaching more than 90% was revealed. The THz imaging of less than 1 mm using a robust 50 mm diameter multilevel THz lens was achieved and demonstrated at 580 GHz frequency.

scholarly journals Development of a Novel Class of Self-Assembling dsRNA Cancer Therapeutics: a Proof of Concept Investigation

2020 ◽  
Author(s):  
Vishwaratn Asthana ◽  
Brett S. Stern ◽  
Yuqi Tang ◽  
Pallavi Bugga ◽  
Ang Li ◽  
...  
Keyword(s):  
Fusion Gene ◽  
Cancer Therapeutics ◽  
Treatment Modalities ◽  
Functional Coupling ◽  
Proof Of Concept ◽  
Cancer Resistance ◽  
Self Assembling ◽  
Modified Dna ◽  
Difficult Challenge ◽  
Sarcoma Cells

AbstractCancer has proven to be an extremely difficult challenge to treat. Several fundamental issues currently underlie cancer treatment including differentiating self from non-self, functional coupling of the recognition and therapeutic components of various therapies, and the propensity of cancerous cells to develop resistance to common treatment modalities via evolutionary pressure. Given these limitations, there is an increasing need to develop an all-encompassing therapeutic that can uniquely target malignant cells, decouple recognition from treatment, and overcome evolutionarily driven cancer resistance. We describe herein, a new class of programmable self-assembling dsRNA-based cancer therapeutics, that uniquely targets aberrant genetic sequences, and in a functionally decoupled manner, undergoes oncogenic RNA activated displacement (ORAD), initiating a therapeutic cascade that induces apoptosis and immune activation. As a proof-of-concept, we show that RNA strands targeting the EWS/Fli1 fusion gene in Ewing Sarcoma cells that are end-blocked with phosphorothioate bonds and additionally sealed with a 2’-U modified DNA protector can be used to induce specific and potent killing of cells containing the target oncogenic sequence, but not wildtype.

High-Resolution Tolerance Against Noise Imaging Technique Based on Active Shift of Optical Axis

2011 ◽  
Vol 5 (2) ◽  
pp. 206-211 ◽  
Author(s):  
Shin Usuki ◽  
◽  
Kenjiro T. Miura ◽  
Keyword(s):  
Optical Imaging ◽  
Optical Axis ◽  
Glass Plate ◽  
Computational Cost ◽  
Numerical Aperture ◽  
Image Resolution ◽  
Objective Lens ◽  
Optical Parameters ◽  
Modulation Transfer ◽  
Pixel Resolution

Optical imaging resolution is determined by both optical parameters such as light wavelength and the objective lens Numerical Aperture (NA) and by spatial sampling such as Charge-Coupled Device (CCD) camera pixel size. Focused on improving optical imaging pixel resolution, we reviewed multiframe Super-Resolution (SR) implemented in previous measurement to improve image resolution, but found its computational cost to high and calculation too long. Pixeldisplacement estimation also adversely affects resulting image quality and is difficult to apply practically due to SR registration calculation sensitivity to noise. The resolution improvement we have proposed uses active subpixel shifting of the optical axis based on actively controlling spatial image displacement using a glass-plate-parallel substrate and a galvano scanner. Multiframe SR registration is used but without pixel-displacement estimation. Theoretically, our proposal may improve image resolution stably at higher speed but to clarify this, we developed optics and rebuilt the multiframe SR.We then computationally analyzed improved resolution and noise tolerance using a Modulation Transfer Function (MTF). Optical and aliasing noise have been suppressed and image resolution improved in high measurement, making higherresolution imaging faster and cheaper thanks to our proposal.

scholarly journals Correlation Plenoptic Imaging: An Overview

2018 ◽  
Vol 8 (10) ◽  
pp. 1958 ◽  
Author(s):  
Francesco Di Lena ◽  
Francesco Pepe ◽  
Augusto Garuccio ◽  
Milena D’Angelo
Keyword(s):  
State Of The Art ◽  
3D Visualization ◽  
Numerical Aperture ◽  
Image Resolution ◽  
Depth Of Field ◽  
Ghost Imaging ◽  
Temporal Correlations ◽  
Entangled Photon Pairs ◽  
Spatio Temporal ◽  
Plenoptic Imaging

Plenoptic imaging (PI) enables refocusing, depth-of-field (DOF) extension and 3D visualization, thanks to its ability to reconstruct the path of light rays from the lens to the image. However, in state-of-the-art plenoptic devices, these advantages come at the expenses of the image resolution, which is always well above the diffraction limit defined by the lens numerical aperture (NA). To overcome this limitation, we have proposed exploiting the spatio-temporal correlations of light, and to modify the ghost imaging scheme by endowing it with plenoptic properties. This approach, named Correlation Plenoptic Imaging (CPI), enables pushing both resolution and DOF to the fundamental limit imposed by wave-optics. In this paper, we review the methods to perform CPI both with chaotic light and with entangled photon pairs. Both simulations and a proof-of-principle experimental demonstration of CPI will be presented.

scholarly journals Ultrathin dual-mode vortex beam generator based on anisotropic coding metasurface

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Liang Zhang ◽  
Jie Guo ◽  
Tongyu Ding
Keyword(s):  
Communication Systems ◽  
Single Layer ◽  
Wireless Communication Systems ◽  
Vortex Beam ◽  
Proof Of Concept ◽  
Dual Mode ◽  
Polarized Waves ◽  
Linearly Polarized ◽  
Potential Applications ◽  
Incident Waves

AbstractIn this paper, an anisotropic coding metasurface is proposed to achieve dual-mode vortex beam generator by independently manipulating the orthogonally linearly polarized waves. The metasurface is composed of ultrathin single-layer ground-backed Jerusalem cross structure, which can provide complete and independent control of the orthogonally linearly polarized incident waves with greatly simplified design process. As proof of concept, a metasurface is designed to generate vortex beams with different topological charges under orthogonal polarizations operating at 15 GHz. Experimental measurements performed on fabricated prototype reveal high quality, and show good agreements with theoretical designs and simulation results. Such ultrathin dual-mode vortex beam generator may find potential applications in wireless communication systems in microwave region.

scholarly journals Electrically Tunable Lenses: A Review

2021 ◽  
Vol 8 ◽  
Author(s):  
Leihao Chen ◽  
Michele Ghilardi ◽  
James J. C. Busfield ◽  
Federico Carpi
Keyword(s):  
Focal Length ◽  
Consumer Electronics ◽  
Smart Phones ◽  
Visible Range ◽  
Thermal Coupling ◽  
Proof Of Concept ◽  
Range Imaging ◽  
Spatial Continuity ◽  
Tunable Lenses ◽  
Glass Lenses

Optical lenses with electrically controllable focal length are of growing interest, in order to reduce the complexity, size, weight, response time and power consumption of conventional focusing/zooming systems, based on glass lenses displaced by motors. They might become especially relevant for diverse robotic and machine vision-based devices, including cameras not only for portable consumer electronics (e.g. smart phones) and advanced optical instrumentation (e.g. microscopes, endoscopes, etc.), but also for emerging applications like small/micro-payload drones and wearable virtual/augmented-reality systems. This paper reviews the most widely studied strategies to obtain such varifocal “smart lenses”, which can electrically be tuned, either directly or via electro-mechanical or electro-thermal coupling. Only technologies that ensure controllable focusing of multi-chromatic light, with spatial continuity (i.e. continuous tunability) in wavefronts and focal lengths, as required for visible-range imaging, are considered. Both encapsulated fluid-based lenses and fully elastomeric lenses are reviewed, ranging from proof-of-concept prototypes to commercially available products. They are classified according to the focus-changing principles of operation, and they are described and compared in terms of advantages and drawbacks. This systematic overview should help to stimulate further developments in the field.

scholarly journals Modeling of Infrared–Visible Sum Frequency Generation Microscopy Images of a Giant Liposome

2016 ◽  
Vol 22 (6) ◽  
pp. 1128-1145
Author(s):  
Victor Volkov ◽  
Carole C. Perry
Keyword(s):  
Numerical Aperture ◽  
Image Plane ◽  
Sum Frequency Generation ◽  
Subcellular Organelles ◽  
Sum Frequency ◽  
Nonlinear Responses ◽  
Simulation Results ◽  
Frequency Generation ◽  
Experimental Geometry ◽  
Microscopy Images

AbstractThe article explores the theory of infrared–visible sum frequency generation microscopy of phospholipid envelopes with dimensions larger than the wavelength of the nonlinear emission. The main part of the study concerns derivation and accounting for the contributions of effective nonlinear responses specific to sites on the surfaces of a bilayer envelope and their dependence on polarization condition and experimental geometry. The nonlinear responses of sites are mapped onto the image plane according to their emission directions and the numerical aperture of a sampling microscope objective. According to the simulation results, we discuss possible approaches to characterize the shape of the envelope, to extract molecular hyperpolarizabilities, and to anticipate possible heterogeneity in envelope composition and anisotropy of the environment proximal to the envelope. The modeling approach offers a promising analytic facility to assist connecting microscopy observations in engineered liposomes, cellular envelopes, and subcellular organelles of relatively large dimensions to molecular properties, and hence to chemistry and structure down to available spatial resolution.

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