Large-area photonic structures in freestanding films

2007 ◽  
Vol 91 (10) ◽  
pp. 103114 ◽  
Author(s):  
Francesco Vita ◽  
Daniele E. Lucchetta ◽  
Riccardo Castagna ◽  
Luigino Criante ◽  
Francesco Simoni
Keyword(s):  
Large Area ◽  
Photonic Structures

Synthesis of monodisperse single-crystal Cu2O spheres and their application in generating structural colors

2019 ◽  
Vol 7 (15) ◽  
pp. 4551-4558 ◽  
Author(s):  
Jiajie Bi ◽  
Suli Wu ◽  
Hongbo Xia ◽  
Lu Li ◽  
Shufen Zhang
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Building Blocks ◽  
Large Area ◽  
Structural Colors ◽  
Photonic Structures ◽  
Spray Method ◽  
Solid Spheres

A two-step reductive strategy is developed to synthesize monodisperse single-crystal Cu2O solid spheres at room-temperature. The single-crystal spheres with adjustable diameter were used as building blocks to form amorphous photonic structures by spray method, which exhibits vivid colors. This may open a new way to realize large area film with vivid structure color.

Large‐Area Fabrication of Highly Tunable Hybrid Plasmonic–Photonic Structures Based on Colloidal Lithography and a Photoreconfigurable Polymer

2019 ◽  
Vol 7 (19) ◽  
pp. 1900483 ◽  
Author(s):  
Shiqiang Wang ◽  
Hao Dong ◽  
Fuwei Sun ◽  
Wanlin Zhang ◽  
Yun Liang ◽  
...  
Keyword(s):  
Colloidal Lithography ◽  
Large Area ◽  
Photonic Structures

scholarly journals Growth of III-nitride photonic structures on large area silicon substrates

2006 ◽  
Vol 88 (17) ◽  
pp. 171909 ◽  
Author(s):  
J. Li ◽  
J. Y. Lin ◽  
H. X. Jiang
Keyword(s):  
Silicon Substrates ◽  
Large Area ◽  
Photonic Structures

Microscale screen printing of large-area arrays of microparticles for the fabrication of photonic structures and for optical sorting

2018 ◽  
Vol 6 (44) ◽  
pp. 12031-12037 ◽  
Author(s):  
Mark A. Rose ◽  
T. P. Vinod ◽  
Stephen A. Morin
Keyword(s):  
Screen Printing ◽  
Large Area ◽  
Photonic Structures ◽  
Optical Sorting ◽  
New Strategy ◽  
Potential Applications

This report describes a new strategy, microparticle screen printing (μSP), generally applicable to the fabrication of homo/heterogeneous arrays of functional particles with potential applications in photonics, optoelectronics, and optical sorting/barcoding.

Two-dimensional hexagonal symmetry diffraction pattern by SiO2 photonic structures fabricated by hot embossing

2017 ◽  
Vol 10 (03) ◽  
pp. 1750031
Author(s):  
Liangwei Wang ◽  
Shuai Guo ◽  
Ke Chai ◽  
Liang Liang ◽  
An li ◽  
...  
Keyword(s):  
Diffraction Pattern ◽  
Diffraction Efficiency ◽  
Incident Angle ◽  
Sol Gel ◽  
Hot Embossing ◽  
Single Step ◽  
Two Dimensional ◽  
Hexagonal Symmetry ◽  
Large Area ◽  
Photonic Structures

Using synthesized sol–gel nanoimprint resist, large-area, ordered SiO2 cylindrical and stripe photonic nanostructures with constant aspect ratio have been fabricated by a single-step soft stamp hot embossing nanoimprint. Different from the traditional hot embossing nanoimprint technique, in our imprint process, the external force applied to the soft stamp is provided just by using our hand. Since the stress can be well released, the stamp can be easily released after the hot stage cooling down. So the optical window (K9 glass) substrates with imprinted two-dimensional SiO2 cylindrical photonic nanostructures show good light diffraction property. Also, our experiment demonstrates that with the imprinted sample annealing at 200[Formula: see text]C, the density of SiO2 will be increased and the diffraction efficiency can be further enhanced. In addition, the light splitting characteristic can still keep good for a larger (6 inch) substrate, which has a certain radian. This illustrates that this nanoimprint method can be compatible with the fluctuation of the imprinted substrates. Furthermore, as the distance between two adjacent feature nanostructures is in sub-micro scale, hexagonal symmetry diffraction pattern by the cylindrical photonic structures was realized at normal incidence of monochromatic laser ([Formula: see text]532[Formula: see text]nm). The diffraction efficiency of first order is about 11.2%. Morever, the diffraction pattern and the intensity of the first diffraction order can be modulated just by changing the incident angle of the input laser.

Convergent Beam Electron Diffraction

1978 ◽  
Vol 36 (3) ◽  
pp. 304-315
Author(s):  
G. Lehmpfuhl
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Crystal Surface ◽  
Diffraction Spot ◽  
Crystal Thickness ◽  
Large Area ◽  
Electron Microscopic ◽  
Additional Information ◽  
Microscopic Investigations

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.

TEM Study of a Tilt Boundary in Hot-Pressed Silicon

1981 ◽  
Vol 39 ◽  
pp. 160-161
Author(s):  
C. B. Carter ◽  
J. Rose ◽  
D. G. Ast
Keyword(s):  
Electron Diffraction ◽  
Imaging Technique ◽  
Interface Structure ◽  
Large Area ◽  
Weak Beam ◽  
Lattice Fringe ◽  
Electron Diffraction Technique ◽  
Tilt Boundaries ◽  
Beam Technique ◽  
Twist Boundaries

The hot-pressing technique which has been successfully used to manufacture twist boundaries in silicon has now been used to form tilt boundaries in this material. In the present study, weak-beam imaging, lattice-fringe imaging and electron diffraction techniques have been combined to identify different features of the interface structure. The weak-beam technique gives an overall picture of the geometry of the boundary and in particular allows steps in the plane of the boundary which are normal to the dislocation lines to be identified. It also allows pockets of amorphous SiO2 remaining in the interface to be recognized. The lattice-fringe imaging technique allows the boundary plane parallel to the dislocation to be identified. Finally the electron diffraction technique allows the periodic structure of the boundary to be evaluated over a large area - this is particularly valuable when the dislocations are closely spaced - and can also provide information on the structural width of the interface.

P20 phosphor on polyimide as a large area high-resolution transmission screen for slow scan CCD systems

1995 ◽  
Vol 53 ◽  
pp. 20-21
Author(s):  
C. C. Ahn ◽  
S. Karnes ◽  
M. Lvovsky ◽  
C. M. Garland ◽  
H. A. Atwater ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
High Energy ◽  
Practical Implementation ◽  
Line Pair ◽  
Modulation Transfer ◽  
Large Area ◽  
Ccd Imaging ◽  
Transmission Electron ◽  
The One ◽  
Beam Broadening

The bane of CCD imaging systems for transmission electron microscopy at intermediate and high voltages has been their relatively poor modulation transfer function (MTF), or line pair resolution. The problem originates primarily with the phosphor screen. On the one hand, screens should be thick so that as many incident electrons as possible are converted to photons, yielding a high detective quantum efficiency(DQE). The MTF diminishes as a function of scintillator thickness however, and to some extent as a function of fluorescence within the scintillator substrates. Fan has noted that the use of a thin layer of phosphor beneath a self supporting 2μ, thick Al substrate might provide the most appropriate compromise for high DQE and MTF in transmission electron microcscopes which operate at higher voltages. Monte Carlo simulations of high energy electron trajectories reveal that only little beam broadening occurs within this thickness of Al film. Consequently, the MTF is limited predominantly by broadening within the thin phosphor underlayer. There are difficulties however, in the practical implementation of this design, associated mostly with the mechanical stability of the Al support film.

Study of Tip-Surface Interactions in Scanning Tunneling Microscopy (STM) by Reflection Electron Microscopy (REM)

1990 ◽  
Vol 48 (1) ◽  
pp. 320-321
Author(s):  
W. Lo ◽  
J.C.H. Spence ◽  
M. Kuwabara
Keyword(s):  
High Resolution ◽  
Elastic Strain ◽  
Tunneling Current ◽  
Surface Damage ◽  
Surface Interactions ◽  
Graphite Surface ◽  
Scanning Tunneling ◽  
Large Area ◽  
Tunneling Microscopy ◽  
High Resolution Tem

Work on the integration of STM with REM has demonstrated the usefulness of this combination. The STM has been designed to replace the side entry holder of a commercial Philips 400T TEM. It allows simultaneous REM imaging of the tip/sample region of the STM (see fig. 1). The REM technique offers nigh sensitivity to strain (<10−4) through diffraction contrast and high resolution (<lnm) along the unforeshortened direction. It is an ideal technique to use for studying tip/surface interactions in STM.The elastic strain associated with tunnelling was first imaged on cleaved, highly doped (S doped, 5 × 1018cm-3) InP(110). The tip and surface damage observed provided strong evidence that the strain was caused by tip/surface contact, most likely through an insulating adsorbate layer. This is consistent with the picture that tunnelling in air, liquid or ordinary vacuum (such as in a TEM) occurs through a layer of contamination. The tip, under servo control, must compress the insulating contamination layer in order to get close enough to the sample to tunnel. The contaminant thereby transmits the stress to the sample. Elastic strain while tunnelling from graphite has been detected by others, but never directly imaged before. Recent results using the STM/REM combination has yielded the first direct evidence of strain while tunnelling from graphite. Figure 2 shows a graphite surface elastically strained by the STM tip while tunnelling (It=3nA, Vtip=−20mV). Video images of other graphite surfaces show a reversible strain feature following the tip as it is scanned. The elastic strain field is sometimes seen to extend hundreds of nanometers from the tip. Also commonly observed while tunnelling from graphite is an increase in the RHEED intensity of the scanned region (see fig.3). Debris is seen on the tip and along the left edges of the brightened scan region of figure 4, suggesting that tip abrasion of the surface has occurred. High resolution TEM images of other tips show what appear to be attached graphite flakes. The removal of contamination, possibly along with the top few layers of graphite, seems a likely explanation for the observed increase in RHEED reflectivity. These results are not inconsistent with the “sliding planes” model of tunnelling on graphite“. Here, it was proposed that the force due to the tunnelling probe acts over a large area, causing shear of the graphite planes when the tip is scanned. The tunneling current is then modulated as the planes of graphite slide in and out of registry. The possiblity of true vacuum tunnelling from the cleaned graphite surface has not been ruled out. STM work function measurements are needed to test this.

Illumination from Large Area Light Sources—II

1914 ◽  
Vol 77 (1988supp) ◽  
pp. 82-83
Author(s):  
Herbert E. Ives
Keyword(s):  
Light Sources ◽  
Large Area
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