Simulation Study on Anti-Reflective Effects for Different Submicron-Structures

2011 ◽  
Vol 314-316 ◽  
pp. 123-126
Author(s):  
Hung Yin Tsai ◽  
Mei Ting Lu ◽  
Shao Wei Luo
Keyword(s):  
Flat Surface ◽  
Heat Insulation ◽  
Driving Safety ◽  
Infrared Range ◽  
Aspect Ratios ◽  
Pyramid Structure ◽  
Submicron Structures ◽  
Pyramid Structures ◽  
Car Driving ◽  
Difference Time

Simulation on transmittance for different submicron-structures by finite difference time domain method is studied. The objectives of this study are to discuss transmittance for different submicron-structures. Different structures have different effects of transmittance and reflectance; therefore different sizes, shapes, periods and aspect ratios of submicron-structures are discussed in the current study. High transmittance at the visible waveband and heat insulation at the infrared range are expected for application of car window. The simulation results for flat surface and pyramid structures show that the transmittance increases from 95.7 % to 99.8 % at the wavelength of 760 nm and slightly from 96.0 % to 96.3 % at the infrared range. Though the effect of heat insulation slightly decreases while the infrared passes through the submicron-structures, the high visibility helps for car driving safety. The pyramid structure shows the optimal condition for the application of car window at the aspect ratio of 1 to 2 than other shapes.

Mid-infrared high birefringence As2Se3-based PCF with large nonlinearity and distinctive dispersion by using asymmetric elliptical air hole cladding

2018 ◽  
Vol 32 (03) ◽  
pp. 1850023 ◽  
Author(s):  
Zhanqiang Hui ◽  
Min Yang ◽  
Youkun Zhang ◽  
Meizhi Zhang
Keyword(s):  
Hexagonal Lattice ◽  
Fdtd Method ◽  
Polarization Mode Dispersion ◽  
Infrared Range ◽  
Polarization Direction ◽  
Mid Infrared ◽  
High Birefringence ◽  
Crystal Fiber ◽  
Mode Dispersion ◽  
Difference Time

A novel high birefringence As2Se3-based hexagonal lattice photonic crystal fiber (PCF) is proposed. In the structure, a central defect core and three kinds of elliptical air holes with different major axes length and ellipticity are introduced in the cladding. The finite difference time domain (FDTD) method with perfectly matched layer (PML) absorption boundary conditions are used to simulate the guided modes of the designed PCF. The properties of this PCF are investigated in detail including the birefringence, beat length, dispersion, nonlinearity and polarization mode dispersion in the 2–5 [Formula: see text] mid-infrared range. The results show that for the optimized structure parameters of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], the high birefringence of 0.1192 and beat length of 41.93 [Formula: see text] are obtained. The maximum nonlinearity coefficient of 10,050 w[Formula: see text]km[Formula: see text] and 15,200 w[Formula: see text]km[Formula: see text] for x- and y-polarization modes are achieved. The distinctive dispersion is analyzed, which is all-normal in x-polarization direction while it has two zero dispersion points at 3.18 [Formula: see text] and 3.65 [Formula: see text] in y-polarization direction. The designed PCF with high birefringence, large nonlinearity and distinctive dispersion will be beneficial for mid-infrared fiber sensing, mid-infrared spectroscopy and nonlinear optics applications.

scholarly journals Laser-written colours on silver: optical effect of alumina coating

Nanophotonics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 807-822 ◽  
Author(s):  
Jean-Michel Guay ◽  
Antonino Calà Lesina ◽  
Graham Killaire ◽  
Peter G. Gordon ◽  
Choloong Hahn ◽  
...  
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Flat Surface ◽  
Atomic Layer ◽  
Alumina Coating ◽  
Optical Effect ◽  
Alumina Film ◽  
Flat Surfaces ◽  
Layer Deposition ◽  
Difference Time

AbstractIn this paper we discuss the optical response of laser-written plasmonic colours on silver coated via the atomic layer deposition of alumina. These colours are due to nanoparticles distributed on a flat surface and on a surface with periodic topographical features (i.e. ripples). The colours are observed to shift with increasing alumina film thickness. The colours produced by surfaces with ripples recover their original vibrancy and hue after the deposition of film of thickness ~60 nm, while colours arising from flat surfaces gradually fade and never recover. Analysis of the surfaces identifies periodic topographical features to be responsible for this behaviour. Finite-difference time-domain simulations unravel the role played by the alumina thickness in colour formation and confirm the rotations and recovery of colours for increasing alumina thickness. The coloured surfaces were evaluated for applications in colourimetric and radiometric sensing showing large sensitivities of up to 3.06/nm and 3.19 nm/nm, respectively. The colourimetric and radiometric sensitivities are observed to be colour dependent.

scholarly journals Effects of Smoking Cannabis on Visual Function and Driving Performance. A Driving-Simulator Based Study

2020 ◽  
Vol 17 (23) ◽  
pp. 9033
Author(s):  
Sonia Ortiz-Peregrina ◽  
Carolina Ortiz ◽  
José J. Castro-Torres ◽  
José R. Jiménez ◽  
Rosario G. Anera
Keyword(s):  
Visual Function ◽  
Driving Simulator ◽  
Driving Performance ◽  
Driving Under The Influence ◽  
Driving Safety ◽  
Limited Information ◽  
Baseline Session ◽  
Visual Effects ◽  
Awareness Campaigns ◽  
Car Driving

Cannabis is the most widely used illegal drug in the world. Limited information about the effects of cannabis on visual function is available, and more detail about the possible impact of visual effects on car driving is required. This study investigated the effects of smoking cannabis on vision and driving performance, and whether these effects are correlated. Twenty drivers and occasional users were included (mean (SE) age, 23.3 (1.0) years; five women). Vision and simulated driving performance were evaluated in a baseline session and after smoking cannabis. Under the influence of cannabis, certain visual functions such as visual acuity (p < 0.001), contrast sensitivity (p = 0.004) and stereoacuity (far, p < 0.001; near, p = 0.013) worsened. In addition, there was an overall deterioration of driving performance, with the task of keeping the vehicle in the lane proving more difficult (p < 0.05). A correlation analysis showed significant associations between driving performance and visual function. Thus, the strongest correlations were found between the distance driven onto the shoulder and stereoacuity, for near (ρ = 0.504; p = 0.001) and far distances (ρ = 0.408; p = 0.011). This study provides the first evidence to show that the visual effects of cannabis could impact driving performance, compromising driving safety. The results indicate that information and awareness campaigns are essential for reducing the incidence of driving under the influence of cannabis.

Waste Time or Lose Life: Assessing the Risk of Phoning While Driving

2015 ◽  
pp. 1376-1397
Author(s):  
Christian Collet
Keyword(s):  
Mobile Phone ◽  
Dual Task ◽  
Navigation System ◽  
Driving Safety ◽  
Objective Measures ◽  
Safety Education ◽  
Impaired Driving ◽  
Mobile Phone Use ◽  
Task Conditions ◽  
Car Driving

Several actions and/or operations might interfere with those required during car-driving and thus elicit dual task conditions. Those related to driving itself involve manipulating commands or instruments and should be automated during the learning to drive period to ensure safety. Others, independent of driving may be delayed (eating, smoking a cigarette). Finally, others like manipulating a navigation system or holding a cellphone have potential interference more or less related to driving. The authors now step back about 25 years to analyze the interference between driving and phoning and assess the risk associated with it. Epidemiology provides an overview of mobile phone use and hypotheses about accident causes. If hand-held phones obviously interfere with driving actions, the authors should explain why hands-free kits do not solve all safety concerns. Then, analyzing the operations affected by phoning and describing the objective measures revealing impaired driving performance will address this issue. The authors finally highlight the conditions for relatively safe phone use as well as those that should be banned. Deciding to phone or not will thus depend on driving safety education, during which skills of caution should have been learned.

Driving Competences and Neuropsychological Factors Associated to Driving Counseling in Multiple Sclerosis

2014 ◽  
Vol 20 (5) ◽  
pp. 555-565 ◽  
Author(s):  
Dolors Badenes ◽  
Maite Garolera ◽  
Laura Casas ◽  
Juan Carlos Cejudo-Bolivar ◽  
Jorge de Francisco ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Neuropsychological Tests ◽  
Cognitive Impairments ◽  
Motor Dysfunction ◽  
Driving Safety ◽  
Cognitive Deterioration ◽  
Visuomotor Coordination ◽  
Motor Disability ◽  
Useful Field Of View ◽  
Car Driving

AbstractMultiple Sclerosis (MS) significantly impacts daily living activities, including car driving. To investigate driving difficulties experienced with MS, we compared 50 MS patients with minor or moderate disability and 50 healthy controls (HC) using computerized driving tests (the ASDE driver test and the Useful Field of View (UFOV) test) and neuropsychological tests. Inclusion criteria included being active drivers. We evaluated whether cognitive deterioration in MS is associated with the results of driving tests by comparing MS patients without cognitive deterioration with HC. The results indicated that the MS patients performed worse than the HCs in attention, information processing, working memory and visuomotor coordination tasks. Furthermore, MS patients with cognitive impairments experienced more difficulties in the driving tests than did the non-impaired MS patients. Motor dysfunction associated with MS also played an important role in this activity. The results of this study suggest that MS should be assessed carefully and that special emphasis should be placed on visuomotor coordination and executive functions because patients with minor motor disability and subtle cognitive impairments can pass measures predictive of driving safety. (JINS, 2014, 20, 555–565)

Sign in / Sign up

Export Citation Format

Share Document