scholarly journals Mueller Matrix Polarimetric Imaging Analysis of Optical Components for the Generation of Cylindrical Vector Beams

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1155
Author(s):  
Guadalupe López-Morales ◽  
María del Mar Sánchez-López ◽  
Ángel Lizana ◽  
Ignacio Moreno ◽  
Juan Campos
Keyword(s):  
Liquid Crystal ◽  
Imaging Techniques ◽  
Mueller Matrix ◽  
Imaging Analysis ◽  
Optical Components ◽  
Spatial Homogeneity ◽  
Polarimetric Imaging ◽  
Vector Beams ◽  
Generate Vector

In this work, we performed a Mueller matrix imaging analysis of two commercial optical components usually employed to generate and manipulate vector beams—a radial polarizer and a liquid-crystal q-plate. These two elements generate vector beams by different polarization mechanisms—polarizance and retardance, respectively. The quality of the vector beams relies on the quality of the device that generates them. Therefore, it is of interest to apply the well-established polarimetric imaging techniques to evaluate these optical components by identifying their spatial homogeneity in diattenuation, polarizance, depolarization, and retardance, as well as the spatial variation of the angles of polarizance and retardance vectors. For this purpose, we applied a customized imaging Mueller matrix polarimeter based on liquid-crystal retarders and a polarization camera. Experimental results were compared to the numerical simulations, considering the theoretical Mueller matrix. This kind of polarimetric characterization could be very helpful to the manufacturers and users of these devices.

scholarly journals Liquid Crystal Devices for Beam Steering Applications

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 247
Author(s):  
Rowan Morris ◽  
Cliff Jones ◽  
Mamatha Nagaraj
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Adaptive Optics ◽  
Beam Steering ◽  
Optical Components ◽  
Advantages And Disadvantages ◽  
Liquid Crystal Devices

Liquid crystals are valuable materials for applications in beam steering devices. In this paper, an overview of the use of liquid crystals in the field of adaptive optics specifically for beam steering and lensing devices is presented. The paper introduces the properties of liquid crystals that have made them useful in this field followed by a more detailed discussion of specific liquid crystal devices that act as switchable optical components of refractive and diffractive types. The relative advantages and disadvantages of the different devices and techniques are summarised.

47‐5: Distinguished Paper: Development of Reversed‐Dispersion Liquid‐Crystal Film to Improve the Display Quality of HDR‐IPS Panels

2021 ◽  
Vol 52 (1) ◽  
pp. 650-653
Author(s):  
Tatsuya Iwasaki ◽  
Yuki Nakamura ◽  
Toshikazu Sumi ◽  
Katsufumi Ohmuro ◽  
Masaaki Suzuki ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Crystal Film ◽  
Display Quality

scholarly journals Titanium-Based Microbolometers: Control of Spatial Profile of Terahertz Emission in Weak Power Sources

2020 ◽  
Vol 10 (10) ◽  
pp. 3400
Author(s):  
Linas Minkevičius ◽  
Liang Qi ◽  
Agnieszka Siemion ◽  
Domas Jokubauskis ◽  
Aleksander Sešek ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Dark Field ◽  
Spatial Mode ◽  
Contrast Imaging ◽  
Optical Components ◽  
Broadband Antenna ◽  
Power Sources ◽  
Precise Control ◽  
Imaging And Spectroscopy ◽  
And Control

Terahertz (THz) imaging and spectroscopy set-ups require fine optical alignment or precise control of spatial mode profile. We demonstrate universal, convenient and easy-to-use imaging—resonant and broadband antenna coupled ultrasensitive titanium-based—dedicated to accurately adjust and control spatial mode profiles without additional focusing optical components of weak power THz sources. Versatile operation of the devices is shown using different kinds of THz—electronic multiplier sources, optical THz mixer-based frequency domain and femtosecond optoelectronic THz time-domain spectrometers as well as optically pumped molecular THz laser. Features of the microbolometers within 0.15–0.6 THz range are exposed and discussed, their ability to detect spatial mode profiles beyond the antennas resonances, up to 2.52 THz, are explored. Polarization-sensitive mode control possibilities are examined in details. The suitability of the resonant antenna-coupled microbolometers to resolve low-absorbing objects at 0.3 THz is revealed via direct, dark field and phase contrast imaging techniques as well.

Sourcing and Qualifying Passive Polarised 3D TVs

2021 ◽  
Vol 2021 (2) ◽  
pp. 100-1-100-6
Author(s):  
Andrew J. Woods
Keyword(s):  
Liquid Crystal ◽  
3D Display ◽  
Consumer Market ◽  
Testing Technique ◽  
Stereoscopic 3D ◽  
Wide Range ◽  
3D Displays ◽  
Liquid Crystal Shutter ◽  
Rear Projection

Millions of Stereoscopic 3D capable TVs were sold into the consumer market from 2007 through to 2016. A wide range of display technologies were supported including rear-projection DLP, Plasma, LCD and OLED. Some displays supported the Active 3D method using liquid-crystal shutter glasses, and some displays supported the Passive 3D method using circularly polarised 3D glasses. Displays supporting Full-HD and Ultra-HD (4K) resolution were available in sizes ranging from 32" to 86" diagonal. Unfortunately display manufacturers eventually changed their focus to promoting other display technologies and 2016 was the last year that new 3D TVs were made for the consumer market. Fortunately, there are still millions of 3D displays available through the secondhand- market, however it can be difficult to know which displays have 3D display support. This paper will provide a listing of specifically Passive 3D TVs manufactured by LG, however it has been our experience that the 3D quality varied considerably from one display to another hence it is necessary to qualify the quality of the 3D available on these displays using a testing technique that will be described in the paper.

What Does Imaging Add to the Management of Alzheimer's Disease?

CNS Spectrums ◽  
2004 ◽  
Vol 9 (S5) ◽  
pp. 20-23 ◽  
Author(s):  
Gary W. Small
Keyword(s):  
Quality Of Life ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Imaging Techniques ◽  
Screening Tools ◽  
Surrogate Markers ◽  
Genetic Disposition ◽  
Number Of Patients

AbstractThe prevalence of Alzheimer's disease (AD) and dementia continues to rise. However, a significant number of patients are undiagnosed or untreated. Given the complexities of detecting cognitive impairment and the early signs of AD, this review discusses how advances in brain imaging can help assist in improving overall management. Imaging techniques and surrogate markers may provide unique opportunities to diagnose accurately AD in presymptomatic stages with practical consequences for patients, caregivers, and physicians. The possible outcomes for using imaging and surrogate markers as adjuncts to clinical examination and as screening tools for AD, as well as tangible and intangible advantages to early diagnosis and treatment, will be discussed. The specific value of using advanced serial imaging in patients with a genetic disposition to AD will be evaluated. If neurons can be protected from neurodegenerative damage in early stages, this may preserve patient cognition, function, and quality of life, and may confer considerable societal healthcare benefits.

scholarly journals Assessment of Myocardial Viability: A Review of Current Non Invasive Imaging Techniques

2015 ◽  
Vol 1 (3) ◽  
pp. 113 ◽  
Author(s):  
Ahmed Talib
Keyword(s):  
Quality Of Life ◽  
Coronary Artery Disease ◽  
Ventricular Dysfunction ◽  
Imaging Techniques ◽  
Left Ventricular ◽  
Common Cause ◽  
Non Invasive ◽  
Artery Disease ◽  
Impaired Quality

Coronary artery disease (CAD) is the most prevalent and<br />single most common cause of morbidity and mortality1 with<br />the resulting left ventricular dysfunction (LVD) an important<br />complication2. Worldwide, CAD accounts for 5.7 million new<br />cases per year, of these 1.3 million in Europe alone3. In addition,<br />it imposes a substantial share of health service resources and<br />expenses, an impaired quality of life, disability and high social<br />cost3,4. Furthermore, LVD itself has been shown to be a powerful<br />determinant of survival2, 5.

scholarly journals The concept of biaxial surface potential and polymer aligning layers in electro-optical cells based on helical nanostructures of ferroelectric liquid crystal

2021 ◽  
Vol 2056 (1) ◽  
pp. 012044
Author(s):  
T P Tkachenko ◽  
A A Zhukov ◽  
E P Pozhidaev
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Surface Potential ◽  
Ferroelectric Liquid Crystal ◽  
Alignment Quality ◽  
Ferroelectric Liquid Crystals ◽  
Helical Pitch

Abstract The paper considers the possibility of controlling the alignment quality of helical nanostructures of ferroelectric liquid crystals (FLCs) within the concept of biaxial surface potential due to variation the FLCs helical pitch p0 and polymer aligning layers structures.

scholarly journals Generation of arbitrary vector beams with cascaded liquid crystal spatial light modulators

2014 ◽  
Vol 22 (2) ◽  
pp. 1636 ◽  
Author(s):  
Zhen-Yu Rong ◽  
Yu-Jing Han ◽  
Shu-Zhen Wang ◽  
Cheng-Shan Guo
Keyword(s):  
Liquid Crystal ◽  
Spatial Light Modulators ◽  
Arbitrary Vector ◽  
Light Modulators ◽  
Vector Beams

scholarly journals From Mouse to Man and Back: Closing the Correlation Gap between Imaging and Histopathology for Lung Diseases

Diagnostics ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 636 ◽  
Author(s):  
Birger Tielemans ◽  
Kaat Dekoster ◽  
Stijn E. Verleden ◽  
Stefan Sawall ◽  
Bartosz Leszczyński ◽  
...  
Keyword(s):  
Lung Disease ◽  
Disease Progression ◽  
Lung Diseases ◽  
Imaging Techniques ◽  
Treatment Options ◽  
Space Technology ◽  
Study Results ◽  
Life Threatening ◽  
End Stage

Lung diseases such as fibrosis, asthma, cystic fibrosis, infection and cancer are life-threatening conditions that slowly deteriorate quality of life and for which our diagnostic power is high, but our knowledge on etiology and/or effective treatment options still contains important gaps. In the context of day-to-day practice, clinical and preclinical studies, clinicians and basic researchers team up and continuously strive to increase insights into lung disease progression, diagnostic and treatment options. To unravel disease processes and to test novel therapeutic approaches, investigators typically rely on end-stage procedures such as serum analysis, cyto-/chemokine profiles and selective tissue histology from animal models. These techniques are useful but provide only a snapshot of disease processes that are essentially dynamic in time and space. Technology allowing evaluation of live animals repeatedly is indispensable to gain a better insight into the dynamics of lung disease progression and treatment effects. Computed tomography (CT) is a clinical diagnostic imaging technique that can have enormous benefits in a research context too. Yet, the implementation of imaging techniques in laboratories lags behind. In this review we want to showcase the integrated approaches and novel developments in imaging, lung functional testing and pathological techniques that are used to assess, diagnose, quantify and treat lung disease and that may be employed in research on patients and animals. Imaging approaches result in often novel anatomical and functional biomarkers, resulting in many advantages, such as better insight in disease progression and a reduction in the numbers of animals necessary. We here showcase integrated assessment of lung disease with imaging and histopathological technologies, applied to the example of lung fibrosis. Better integration of clinical and preclinical imaging technologies with pathology will ultimately result in improved clinical translation of (therapy) study results.

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