scholarly journals Super black eyespots of the Eyed elater

2019 ◽  
Author(s):  
Victoria L Wong ◽  
Paul E Marek
Keyword(s):  
Incident Light ◽  
Natural World ◽  
Surface Structures ◽  
Anatomical Structures ◽  
Scattering Of Light ◽  
Click Beetle ◽  
Absorption Of Light ◽  
Complete Absorption ◽  
Vertically Aligned ◽  
Scatter Light

Scattering of light by surface structures leading to near complete structural absorption creates an appearance of “super black.” Well known in the natural world from bird feathers and butterfly scales, super black has evolved independently from various anatomical structures. Due to an exceptional ability to harness and scatter light, these biological materials have garnered interest from optical industries. Here we describe the false eyespots of the Eyed elater click beetle, which attains near complete absorption of light by an array of vertically-aligned microtubules. These cone-shaped microtubules are modified hairs (setae) that are localized to eyespots on the dorsum of the beetle, and absorb 96.1% of incident light (at a 24.8° collection angle) in the spectrum between 300 – 700 nm.

scholarly journals Super black eyespots of the Eyed elater

2019 ◽  
Author(s):  
Victoria L Wong ◽  
Paul E Marek
Keyword(s):  
Incident Light ◽  
Natural World ◽  
Surface Structures ◽  
Anatomical Structures ◽  
Scattering Of Light ◽  
Click Beetle ◽  
Absorption Of Light ◽  
Complete Absorption ◽  
Vertically Aligned ◽  
Scatter Light

Scattering of light by surface structures leading to near complete structural absorption creates an appearance of “super black.” Well known in the natural world from bird feathers and butterfly scales, super black has evolved independently from various anatomical structures. Due to an exceptional ability to harness and scatter light, these biological materials have garnered interest from optical industries. Here we describe the false eyespots of the Eyed elater click beetle, which attains near complete absorption of light by an array of vertically-aligned microtubules. These cone-shaped microtubules are modified hairs (setae) that are localized to eyespots on the dorsum of the beetle, and absorb 96.1% of incident light (at a 24.8° collection angle) in the spectrum between 300 – 700 nm.

scholarly journals Structure and pigment make the eyed elater’s eyespots black

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8161 ◽  
Author(s):  
Victoria L. Wong ◽  
Paul E. Marek
Keyword(s):  
Specular Reflection ◽  
Incident Light ◽  
Natural World ◽  
Multiple Reflections ◽  
Anatomical Structures ◽  
Click Beetle ◽  
Combine Structure ◽  
Absorption Of Light ◽  
Complete Absorption ◽  
Vertically Aligned

Surface structures that trap light leading to near complete structural absorption creates an appearance of “super black.” Well known in the natural world from bird feathers and butterfly scales, super black has evolved independently from various anatomical structures. Due to an exceptional ability to reduce specular reflection, these biological materials have garnered interest from optical industries. Here we describe the false eyes of the eyed elater click beetle, which, while not classified as super black, still attains near complete absorption of light partly due to an array of vertically-aligned microtubules. These cone-shaped microtubules are modified hairs (setae) that are localized to eyespots on the dorsum of the beetle, and absorb 96.1% of incident light (at a 24.8° collection angle) in the spectrum between 300–700 nm. Filled with melanin, the setae combine structure and pigment to generate multiple reflections and refractions causing light to travel a greater distance. This light-capturing architecture leaves little light available to receivers and the false eyes appear as deep black making them appear more conspicuous to predators.

Electrochemical preparation of vertically aligned, hollow CdSe nanotubes and their p–n junction hybrids with electrodeposited Cu2O

Nanoscale ◽  
2014 ◽  
Vol 6 (15) ◽  
pp. 9148-9156 ◽  
Author(s):  
Joyashish Debgupta ◽  
Ramireddy Devarapalli ◽  
Shakeelur Rahman ◽  
Manjusha V. Shelke ◽  
Vijayamohanan K. Pillai
Keyword(s):  
Charge Carriers ◽  
Type Ii ◽  
Electrochemical Preparation ◽  
Enhanced Absorption ◽  
Absorption Of Light ◽  
Vertically Aligned ◽  
P Type

Heterojunction (type II) of self standing, vertically aligned CdSe NTs (n-type) with electrodeposited Cu2O (p-type) exhibits excellent photoresponse, resulting from enhanced absorption of light and faster transport of photogenerated charge carriers by CdSe NTs.

Dye-Improved Optical Absorption of Vertically Aligned Silicon Nanowire Arrays Synthesized by Electroless Etching of Silicon Wafer

2014 ◽  
Vol 895 ◽  
pp. 200-203 ◽  
Author(s):  
Hui Chiang Teoh ◽  
Sabar Derita Hutagalung
Keyword(s):  
Silicon Nanowires ◽  
High Performance ◽  
Silicon Nanowire ◽  
Incident Light ◽  
Electroless Etching ◽  
Dye Sensitized ◽  
Silicon Nanowire Arrays ◽  
Wide Range ◽  
Vertically Aligned ◽  
Si Wafer

Silicon nanowires (SiNWs) are important candidate for high performance electronic and optoelectronic devices due to their unique structures, electrical and optical properties. SiNWs were fabricated by silver-assisted electroless etching of Si wafer. Vertically aligned SiNW arrays with length about 8.75 μm and diameter of less than 90 nm have been fabricated. The reflectance of SiNWs without dye (12%) is greatly lower compared to bare Si wafer (25%). Therefore, SiNWs on Si substrate can be used as a good anti-reflection layer for a wide range of incident light. The reflectance of dye-sensitized SiNWs with red, green and blue dyes is 7%, 5.5%, and 5% respectively. The results confirmed that the reflectance of SiNWs with dye is much lower compared to SiNWs without dye and bare Si wafer. It was proven that dye on SiNWs can be used to reduce the reflectance (improved absorption) about 40% compared to SiNWs without dye.

scholarly journals On the theory of scattering of light

1938 ◽  
Vol 166 (926) ◽  
pp. 425-449 ◽  
Keyword(s):  
Scattered Light ◽  
Incident Light ◽  
Incident Beam ◽  
The State ◽  
Reciprocity Relation ◽  
Scattering Of Light ◽  
Plane Parallel ◽  
Solid Media ◽  
State Of Polarization ◽  
Light Components

In a series of recent investigations R. S. Krishnan (1934-8) demonstrated the existence of a new effect which will be called the Krishnan effect. It relates to the state of polarization of the light scattered by certain liquid or solid media in directions normal to the incident beam. To describe the effect let us denote with π the plane parallel to the direction of observation and to that of the incident beam. Since in the experiment this plane is usually horizontal we denote by H the intensity of those scattered light components which vibrate parallel to this plane, and by V those vibrating normal to π. In a similar manner subscripts h or v indicate whether the incident light vibrates parallel or normal to the plane. We distinguish therefore (see fig. 1) the four light components H h , H v , V h and V v . Following Krishnan the depolarizations are defined by P h = V h / H h , p v = H v / V v , p u = ( H h + H v )/( V h / V v ). p u is the depolarization for natural incident light. For most liquids the observations give, in agreement with the theories of temperature scattering, H h = V h = H v , hence p h = 1, p u = 2 p v /(1+ p v ). The Krishnan effect is the observation that in a number of liquid and solid systems p h = V h / H h ≠ 1, and V h = H v . Krishnan has called (2) the reciprocity relation. All observations have given p h < 1, but none of the present theories exclude the possibility that p h may assume values larger than 1.

Scattering of light from entropy fluctuations in 3He–4He mixtures

1968 ◽  
Vol 46 (17) ◽  
pp. 1895-1903 ◽  
Author(s):  
B. N. Ganguly ◽  
A. Griffin
Keyword(s):  
Critical Point ◽  
Concentration Fluctuations ◽  
Complete Analysis ◽  
Second Sound ◽  
Hydrodynamic Equations ◽  
Normal Fluid ◽  
Strongly Coupled ◽  
Scattering Of Light ◽  
First Sound ◽  
Scatter Light

In 1957, Gor'kov and Pitaevskii showed that second sound in 3He–4He mixtures is strongly coupled into the concentration fluctuations, which, in turn, scatter light quite strongly (especially near the critical point). In this paper, we give a more complete analysis of the fluctuations in density, entropy, and concentration. Our discussion is based on the hydrodynamic equations of Khalatnikov, which assume that the 3He atoms move with the normal fluid, and for simplicity we omit all dissipative coefficients. If we limit ourselves to scattering from density and concentration fluctuations, our results for the first and second sound intensities agree essentially with those of Gor'kov and Pitaevskii. Near the critical point, second sound scatters light about six times more strongly than first sound does.

Si Nanoparticle Synthesis and Self – Organization

2002 ◽  
Vol 737 ◽  
Author(s):  
J. D. Fowlkes ◽  
A. J. Pedraza
Keyword(s):  
Incident Light ◽  
Nanoparticle Synthesis ◽  
Laser Pulses ◽  
Self Organization ◽  
Periodic Surface ◽  
Linear Arrays ◽  
Self Organized ◽  
Si Nanoparticle ◽  
Si Nanoparticles ◽  
Scatter Light

ABSTRACTSi nanoparticle linear arrays have been produced by pulsed KrF laser irradiation in inert atmospheres. The Si nanoparticles have a Gaussian size distribution with a mean diameter of 2.9 nm and a FWHM of 2 nm. The self – organized lines are spaced at a distance approximately equal to the laser beam wavelength, λ. The evolution of this self – organization process and that of laser – induced periodic surface structures (LIPSS) are closely related. The nanoparticles scatter light that interferes with the incident light. Similar to LIPSS, the inhomogeneous deposition of laser light due to this interference pattern created at the surface drives the particle formation and clustering. A detailed study of the clustering formation as a function of the laser pulses is presented.

scholarly journals An Explanation of Subsurface Optical Pathways through Food Myosystems and their Effect on Colorimetry

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Howard James Swatland
Keyword(s):  
Diffuse Reflectance ◽  
Incident Light ◽  
Muscle Fibers ◽  
Anaerobic Glycolysis ◽  
Post Mortem ◽  
Electrical Capacitance ◽  
Scattering Of Light ◽  
Light Passing ◽  
Chromaticity Coordinates ◽  
Cie Chromaticity

Light may pass along and across the long axes of muscle fibers in any food myosystem. Thus, incident light may be scattered in several ways before some of it reappears at the surface as diffuse reflectance.  Pathways may be short if scattering is strong, or long if scattering is weak. Short pathways minimize selective absorbance by chromophores such as myoglobin, while long pathways maximize selective absorbance.  Many food myosystems exhibit a post-mortem decrease in pH caused by anaerobic glycolysis with a series of microstructural changes – glycogen granules between myofibrils are lost, myofibrils shrink laterally as myofilaments move closer together, water moves from within myofibrils to the space between them, muscle fiber membranes leak and lose their electrical capacitance, and myoglobin is flushed into the fluid filled spaces between muscle fibers. These changes increase scattering of light passing across the long axes of muscle fibers.  Scattering of light along muscle fibers is caused by sarcomere discs (A-bands).  Interference from one or a small number of sarcomere discs may cause iridescence, but in most cases interference from numerous discs causes achromatic diffuse reflectance. Commission International de l’Éclairage (CIE) chromaticity coordinates were calculated for various subsurface optical pathways. Pathways across versus along muscle fibers had a strong effect on CIE y (r = 0.84, P < 0.01) and an even stronger effect on CIE Y% (r = 0.95, P < 0.005).

Cuticular microstructures and their relationship to structural color and transpiration in the terrestrial isopod Porcellionides pruinosus

1985 ◽  
Vol 63 (3) ◽  
pp. 649-656 ◽  
Author(s):  
Neil F. Hadley ◽  
Gregory M. Hendricks
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Incident Light ◽  
Dorsal Surface ◽  
Surface Structures ◽  
Spherical Particles ◽  
Structural Color ◽  
Cuticular Transpiration ◽  
Terrestrial Isopod ◽  
Scanning Electron

The microstructure of the dorsal surface of the terrestrial isopod Porcellionides pruinosus was examined by scanning electron microscopy. Surface structures detected include sensory tricorns, spherical particles (balls) of various diameter, plates formed from the fusion of adjacent balls, and extremely small granules. A rod-shaped bacterium was also present on the surface of most individuals. The cuticular balls scatter and reflect incident light, producing a grayish white color or frosted appearance in most intermolt isopods. Prior to a molt, individuals are characteristically brown or unfrosted owing to the loss of the balls from the cuticle surface. New balls appear within a few hours following ecdysis and the isopod soon reacquires the frosted appearance. The balls are insoluble in lipid solvents and are also resistant to acetic acid and KOH. Higher water loss rates in unfrosted versus frosted individuals suggest that one function of the balls is to reduce cuticular transpiration in this species.

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