Homogeneity of Oxide Air-Sphere Crystals from Millimeter to 100-nm Length Scales:  A Probe for Macroporous Photonic Crystal Formation

2004 ◽  
Vol 16 (12) ◽  
pp. 2425-2432 ◽  
Author(s):  
Lydia Bechger ◽  
Willem L. Vos
Keyword(s):  
Photonic Crystal ◽  
Crystal Formation ◽  
Length Scales

Nano-photonic crystal formation on highly-doped n-type silicon

2015 ◽  
Vol 11 (1) ◽  
pp. 10-12 ◽  
Author(s):  
Fu-ru Zhong ◽  
Zhen-hong Jia
Keyword(s):  
Photonic Crystal ◽  
Crystal Formation ◽  
Type Silicon

scholarly journals Evolution of single gyroid photonic crystals in bird feathers

2021 ◽  
Vol 118 (23) ◽  
pp. e2101357118
Author(s):  
Vinodkumar Saranathan ◽  
Suresh Narayanan ◽  
Alec Sandy ◽  
Eric R. Dufresne ◽  
Richard O. Prum
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystals ◽  
Three Dimensional ◽  
Optical Length ◽  
Length Scales ◽  
Structural Colors ◽  
Rich Diversity ◽  
Efficient Alternative ◽  
Alternative Routes ◽  
Channel Type

Vivid, saturated structural colors are conspicuous and important features of many animals. A rich diversity of three-dimensional periodic photonic nanostructures is found in the chitinaceous exoskeletons of invertebrates. Three-dimensional photonic nanostructures have been described in bird feathers, but they are typically quasi-ordered. Here, we report bicontinuous single gyroid β-keratin and air photonic crystal networks in the feather barbs of blue-winged leafbirds (Chloropsis cochinchinensis sensu lato), which have evolved from ancestral quasi-ordered channel-type nanostructures. Self-assembled avian photonic crystals may serve as inspiration for multifunctional applications, as they suggest efficient, alternative routes to single gyroid synthesis at optical length scales, which has been experimentally elusive.

scholarly journals 2D-Heterostructure Photonic Crystal Formation for On-Chip Polarization Division Multiplexing

Photonics ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 313
Author(s):  
Nikolay Lvovich Kazanskiy ◽  
Muhammad Ali Butt ◽  
Svetlana Nikolaevna Khonina
Keyword(s):  
Photonic Crystal ◽  
Transmission Loss ◽  
Numerical Study ◽  
Extinction Ratio ◽  
Polarized Light ◽  
Crystal Formation ◽  
Dimensional Finite Element ◽  
On Chip ◽  
Polarization Of Light ◽  
Polarization Division Multiplexing

Herein, we offer a numerical study on the devising of a unique 2D-heterostructure photonic crystal (PC) that can split two orthogonally polarized light waves. The analysis is performed via a two-dimensional finite element method (2D-FEM) by utilizing the COMSOL Multiphysics software. The device consists of two discrete designs of PC formation. The first PC formation is optimized so that it permits both TE- and TM-polarization of light to transmit through it. Whereas, the second PC formation possesses a photonic bandgap (PBG) only for TE-polarized light. These two formations are combined at an angle of 45°, resulting in a reflection of self-collimated TE-polarized light at an angle of 90° owing to the PBG present in the second PC formation. While permitting the self-collimated TM-polarized light wave to travel uninterrupted. The proposed device has a small footprint of ~10.9 μm2 offering low transmission loss and high polarization extinction ratio which makes it an ideal candidate to be employed as an on-chip polarization division multiplexing system.

scholarly journals 2D-Heterostructure Photonic Crystal Formation for On-Chip Polarization Division Multiplexing

2021 ◽  
Author(s):  
Nikolay L. Kazanskiy ◽  
Muhammad Ali Butt ◽  
Svetlana Nikolaevna Khonina
Keyword(s):  
Photonic Crystal ◽  
Transmission Loss ◽  
Numerical Study ◽  
Extinction Ratio ◽  
Polarized Light ◽  
Crystal Formation ◽  
Dimensional Finite Element ◽  
On Chip ◽  
Polarization Of Light ◽  
Polarization Division Multiplexing

Herein, we offer a numerical study on the devising of a unique 2D-heterostructure Photonic crystal (PC) that can split two orthogonally polarized light waves. The analysis is performed via a two-dimensional finite element method (2D-FEM) by utilizing COMSOL Multiphysics software. The device consists of two discrete designs of PC formation. The first PC formation is optimized so that it permits both TE and TM-polarization of light to transmit through it. Whereas the second PC formation possesses a Photonic Bandgap (PBG) only for TE-polarized light. These two formations are combined at an angle of 45 degrees, resulting in a reflection of self-collimated TE-polarized light at an angle of 90 degrees owing to the PBG present in the second PC formation. While permitting the self-collimated TM-polarized light wave to travel uninterrupted. The proposed device has a small footprint of ~10.5 μm2 offering low transmission loss and high polarization extinction ratio which makes it an ideal candidate to be employed as an on-chip polarization division multiplexing system.

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

Techniques for cryoultramicrotomy of propane jet frozen biological samples

1986 ◽  
Vol 44 ◽  
pp. 260-261
Author(s):  
B. Craig ◽  
L. Hawkey ◽  
A. LeFurgey
Keyword(s):  
Freeze Fracture ◽  
Freeze Substitution ◽  
Heart Cells ◽  
Crystal Formation ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Chick Heart ◽  
Embryonic Chick Heart ◽  
A New Technique

Ultra-rapid freezing followed by cryoultramicrotomy is essential for the preservation of diffusible elements in situ within cells prior to scanning transmission electron microscopy and quantitative energy dispersive x-ray microanalysis. For cells or tissue fragments in suspension and for monolayer cell cultures, propane jet freezing provides cooling rates greater than 30,000°C/sec with regions up to 40μm in thickness free of significant ice crystal formation. While this method of freezing has frequently been applied prior to freeze fracture or freeze substitution, it has not been widely utilized prior to cryoultramicrotomy and subsequent x-ray microanalytical studies. This report describes methods devised in our laboratory for cryosectioning of propane jet frozen kidney proximal tubule suspensions and cultured embryonic chick heart cells, in particular a new technique for mounting frozen suspension specimens for sectioning. The techniques utilize the same specimen supports and sample holders as those used for freeze fracture and freeze substitution and should be generally applicable to any cell suspension or culture preparation.

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