The waveguide invariant: Wavefield structure, ray stability, time spreads and modal dispersion

2021 ◽  
Vol 150 (4) ◽  
pp. A280-A280
Author(s):  
Michael G. Brown
Keyword(s):  
Modal Dispersion ◽  
Waveguide Invariant ◽  
Stability Time

scholarly journals Image reconstruction through a multimode fiber with a simple neural network architecture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Changyan Zhu ◽  
Eng Aik Chan ◽  
You Wang ◽  
Weina Peng ◽  
Ruixiang Guo ◽  
...  
Keyword(s):  
Neural Network ◽  
Image Reconstruction ◽  
Network Architecture ◽  
Neural Network Architecture ◽  
Training Time ◽  
Modal Dispersion ◽  
Multimode Fibers ◽  
Speckle Patterns ◽  
Hidden Layer ◽  
Simple Neural Network

AbstractMultimode fibers (MMFs) have the potential to carry complex images for endoscopy and related applications, but decoding the complex speckle patterns produced by mode-mixing and modal dispersion in MMFs is a serious challenge. Several groups have recently shown that convolutional neural networks (CNNs) can be trained to perform high-fidelity MMF image reconstruction. We find that a considerably simpler neural network architecture, the single hidden layer dense neural network, performs at least as well as previously-used CNNs in terms of image reconstruction fidelity, and is superior in terms of training time and computing resources required. The trained networks can accurately reconstruct MMF images collected over a week after the cessation of the training set, with the dense network performing as well as the CNN over the entire period.

scholarly journals Silicon integrated multi-mode ring resonator

Nanophotonics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 1265-1272
Author(s):  
Mengyuan Ye ◽  
Chunlei Sun ◽  
Yu Yu ◽  
Yunhong Ding ◽  
Xinliang Zhang
Keyword(s):  
Integrated Circuit ◽  
Ring Resonator ◽  
Rapid Development ◽  
Essential Element ◽  
Single Mode ◽  
Modal Dispersion ◽  
Waveguide Width ◽  
Mode Division Multiplexing ◽  
Evanescent Coupling ◽  
Multi Mode

Abstract Ring resonator is an essential element in silicon integrated circuit, it is widely used as filter, wavelength multiplexer and switch in single-mode operation regime. As the rapid development of mode division multiplexing (MDM) technique, ring resonator that can process multi-mode signals simultaneously and uniformly is highly desired. However, the severe modal dispersion makes identical transmission for different modes very hard. In this paper, by breaking through the limitation of conventional multi-mode manipulation design with evanescent coupling or mode interference, we propose and demonstrate a multi-mode ring resonator (MMRR) inspired by the free space geometric optics. Arbitrary number of supporting modes can be achieved by simply widening the waveguide width. For proof-of-concept demonstration, an MMRR supporting four modes is fabricated with uniform transmittance. Furthermore, architecture of cascaded four MMRRs are also demonstrated experimentally.

Experimental verification of modal dispersion free characteristics in a two-mode optical fiber

1979 ◽  
Vol 15 (1) ◽  
pp. 6-8 ◽  
Author(s):  
K. Kitayama ◽  
Y. Kato ◽  
S. Seikai ◽  
N. Uchida ◽  
M. Ikeda
Keyword(s):  
Optical Fiber ◽  
Experimental Verification ◽  
Modal Dispersion

Multimode-Interference-Based Waveguide Crossing in Two-Dimensional Cubic Photonic Crystal

2013 ◽  
Vol 284-287 ◽  
pp. 2876-2879
Author(s):  
Yih Bin Lin ◽  
Jen Hao Cheng ◽  
Rei Shin Chen ◽  
Ting Chung Yu ◽  
Ju Feng Liu ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Integrated Circuits ◽  
Expansion Method ◽  
Transmission Efficiency ◽  
Multimode Interference ◽  
Plane Wave Expansion Method ◽  
Modal Dispersion ◽  
Optical Integrated Circuits ◽  
Difference Time ◽  
Novel Design

A novel design of photonic crystal waveguide crossing based on multimode-interference (MMI) structure is proposed. Two structures of difference device lengths are simulated and studied. The proposed structures have high transmission efficiency for a wide bandwidth. The crosstalk is -26dB with device length of 12 lattice periods and -39dB with device length of 24 lattice periods. The plane wave expansion method and finite-difference time-domain method are used to calculate the modal dispersion curve and field propagation, respectively. The proposed MMI-based waveguide crossing has the potential to be practical in high-density optical integrated circuits.

scholarly journals Standardization of dot-ELISA for the serological diagnosis of toxocariasis and comparision of the assay with ELISA

1992 ◽  
Vol 34 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Eide Dias Camargo ◽  
Paulo Mutuko Nakamura ◽  
Adelaide José Vaz ◽  
Marcos Vinícius da Silva ◽  
Pedro Paulo Chieffi ◽  
...  
Keyword(s):  
Low Cost ◽  
Clinical Signs ◽  
Toxocara Canis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Specific Antibodies ◽  
Normal Individuals ◽  
Before And After ◽  
Dot Elisa ◽  
Stability Time

The dot-enzyme-linked immunosorbent assay (dot-ELISA) was standardized using somatic (S) and excretory-secretory (ES) antigens of Toxocara-canis for the detection of specific antibodies in 22 serum samples from children aged 1 to 15 years, with clinical signs of toxocariasis. Fourteen serum samples from apparently normal individuals and 28 sera from patients with other pathologies were used as controls. All samples were used before and after absorption with Ascaris suum extract. When the results were evaluated in comparison with ELISA, the two tests were found to have similar sensitivity, but dot-ELISA was found to be more specific in the presence of the two antigens studied. Dot-ELISA proved to be effective for the diagnosis of human toxocariasis, presenting advantages in terms of yield, stability, time and ease of execution and low cost.

Effects of the Preceding Scale on Melodic Interval Judgment in Terms of Equality and Size

1991 ◽  
Vol 9 (1) ◽  
pp. 47-70 ◽  
Author(s):  
Minoru Tsuzaki
Keyword(s):  
Music Cognition ◽  
Musical Ability ◽  
Trained Subjects ◽  
Standard Interval ◽  
Modal Dispersion ◽  
Subjective Equality ◽  
Related Aspect ◽  
The Relationship ◽  
Diatonic Scale

In an investigation of interactions between scales and intervals in music cognition, melodic intervals were judged in three preceding-scale contexts: diatonic, chromatic, and no scale. Musically less trained and highly trained subjects compared standard and comparison intervals using three response categories: smaller, equal, and larger. Standard intervals began with notes B or C and ascended by 100, 150, or 200 cents. Discriminal dispersion was estimated for each combination of standard and comparison intervals, based on the assumption that the bandwidth of subjective equality was constant. The dispersion width and the modal dispersion corresponded to the equality- related and sizerelated aspects of interval judgments, respectively. The size-related aspect was strongly influenced by the size of the standard intervals. The point of balance, which corresponds to the traditional point of subjective equality (PSE), tended to be smaller as the standard interval became larger. It was, however, anchored to the point of musical equality when the standard interval began with the tonic. The equality-related aspect was influenced by the relationship between the preceding scale and the intervals to be judged. The diatonic preceding scale differentiated the intervals by their positions along the scale, that is, a sharp discriminal dispersion was estimated when the judged intervals were congruent with the diatonic scale. Such differentiation was not clearly observed in the chromatic condition. The relationship between these two aspects of interval judgment and the subject's musical ability is discussed.

scholarly journals A method to determine the acoustic reflection and absorption coefficients of porous media by using modal dispersion in a waveguide

2014 ◽  
Vol 136 (6) ◽  
pp. 2947-2958 ◽  
Author(s):  
Jevgenija Prisutova ◽  
Kirill Horoshenkov ◽  
Jean-Philippe Groby ◽  
Bruno Brouard
Keyword(s):  
Porous Media ◽  
Absorption Coefficients ◽  
Acoustic Reflection ◽  
Modal Dispersion
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