A Comparison of an Improved Design for Two Integrated Optical Isolators Based on Nonreciprocal Mach-Zehnder Interferometry

1998 ◽  
Vol 517 ◽  
Author(s):  
N. Bahlmann ◽  
M. Lohmeyer ◽  
M. Wallenhorst ◽  
H. Dötsch ◽  
P. Hertel
Keyword(s):  
Phase Shift ◽  
Double Layer ◽  
Opposite Sign ◽  
Absolute Value ◽  
Integrated Optical ◽  
Fabrication Tolerances ◽  
The Difference ◽  
Optical Isolators ◽  
Improved Design ◽  
Backward Propagation

AbstractNonreciprocal rib waveguide structures can be used to realize integrated optical isolators. The nonreciprocal phase shift is the difference between the forward and backward propagation constants of TM modes in magneto-optic waveguides. It can be optimized with respect to absolute value and temperature dependence if double layer waveguides with different magnetic and nonmagnetic layers are prepared. In this paper we propose an improved design for two different Mach-Zehnder interferometer isolators the nonreciprocal parts of which are formed by such double layer waveguides. One concept utilizes a nonreciprocal and a reciprocal arm. In the other case both arms are nonreciprocal but with opposite sign of the nonreciprocal phase shift. A particular property of both concepts is that the lengths of the nonreciprocal arms are well defined. The rest of the interferometer is made by reciprocal rib waveguides. Therefore, the nonreciprocal phase shift is well known. The concepts are compared with regard to isolation ratio, forward losses and fabrication tolerances. Moreover, we simulate the entire isolator by a finite difference beam propagation calculation.

Radiatively Coupled Waveguide Concept for an Integrated Magneto-Optic Circulator

1998 ◽  
Vol 517 ◽  
Author(s):  
M. Lohmeyer ◽  
M. Shamonin ◽  
N. Bahlmann ◽  
P. Hertel ◽  
H. Dotsch
Keyword(s):  
Transmission Loss ◽  
Specific Form ◽  
Optical Channels ◽  
Integrated Optical ◽  
Transfer Behavior ◽  
Fabrication Tolerances ◽  
Optical Isolators ◽  
Geometry Parameter ◽  
Novel Devices ◽  
Isolation Performance

AbstractThree-guide couplers with multimode central waveguides allow for remote coupling between optical channels. A simple three mode approximation turns out to be sufficient for the description of the main features of the power transfer behavior. The specific form of the relevant modes suggests the design of integrated optical isolators and circulators based on magnetic garnet materials. These novel devices are superior to conventional nonreciprocal couplers with respect to the total length and admissible fabrication tolerances. We characterize the isolation performance and the transmission loss for the proposed devices by propagating mode simulations and estimate the influence of geometry parameter deviations.

COUPLING EFFICIENCY OF METAMATERIAL MAGNETOOPTICAL INTEGRATED ISOLATOR

2009 ◽  
Vol 23 (22) ◽  
pp. 4675-4683 ◽  
Author(s):  
HALA J. EL-KHOZONDAR ◽  
RIFA J. EL-KHOZONDAR ◽  
MOHAMMED M. SHABAT
Keyword(s):  
Communication Systems ◽  
Coupling Efficiency ◽  
Transverse Magnetic ◽  
Coupling Coefficients ◽  
Optical Isolator ◽  
Integrated Optical ◽  
Phase Constant ◽  
The Difference ◽  
Backward Propagation ◽  
The Magnetic Field

Nonreciprocal devices such as isolators are well-known in light wave communication systems. The integrated optical isolator is presented where the magnetic field modes propagate perpendicular to the in-plane magnetization of a planar magnetooptical waveguide. The cladding and film of optical isolator are made of magnetic materials with magnetization adjusted to be parallel to their plan. The substrate is filled with new artificial metamaterials (MTMs). The dispersion equation of the transverse magnetic (TM) fields is derived. The difference Δβ between the phase constant for forward and backward propagation is calculated numerically for different values of MTMs permittivity (εs) and permeability (μs). Results show that the cutoff thickness is different for forward and backward propagation and varies with the MTMs parameters. The cutoff thickness of the isolator is selected such that the coupling coefficients of the isolator with optical fiber are obviously different for forward and backward propagation.

scholarly journals Stochastic Comparisons of Some Distances between Random Variables

Mathematics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 981
Author(s):  
Patricia Ortega-Jiménez ◽  
Miguel A. Sordo ◽  
Alfonso Suárez-Llorens
Keyword(s):  
Financial Risk ◽  
Sufficient Conditions ◽  
Random Variables ◽  
Stochastic Ordering ◽  
Random Variable ◽  
Distribution Functions ◽  
Stochastic Comparisons ◽  
Stochastic Orderings ◽  
Absolute Value ◽  
The Difference

The aim of this paper is twofold. First, we show that the expectation of the absolute value of the difference between two copies, not necessarily independent, of a random variable is a measure of its variability in the sense of Bickel and Lehmann (1979). Moreover, if the two copies are negatively dependent through stochastic ordering, this measure is subadditive. The second purpose of this paper is to provide sufficient conditions for comparing several distances between pairs of random variables (with possibly different distribution functions) in terms of various stochastic orderings. Applications in actuarial and financial risk management are given.

A Direct Rotatability Criterion for Spherical Four-Bar Linkages

1995 ◽  
Vol 117 (4) ◽  
pp. 597-600 ◽  
Author(s):  
K. C. Gupta ◽  
R. Ma
Keyword(s):  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Absolute Value ◽  
The Difference ◽  
Necessary And Sufficient ◽  
Four Bar Linkage

The necessary and sufficient conditions for the full input rotatability in a spherical four-bar linkage are proved. The direct criterion is: for all twist angles α in the range [0, π], the excess (deficit) of the sum of the frame and input twist angles over (from) π should, in absolute value, be greater than that for the coupler and follower twist angles; the difference between the follower and input twist angles, in absolute value, should be greater than that for the coupler and follower twist angles. Application of the direct criterion to full rotatability of other links are discussed and some variations in the form of the criterion are developed.

Analogue of a theorem of Khintchine in fields of formal power series

1966 ◽  
Vol 62 (4) ◽  
pp. 637-642 ◽  
Author(s):  
T. W. Cusick
Keyword(s):  
Power Series ◽  
Positive Constant ◽  
Classical Result ◽  
Real Numbers ◽  
Linear Forms ◽  
Absolute Value ◽  
The Difference ◽  
Image Position ◽  
Formal Power ◽  
Positive Integers

For a real number λ, ‖λ‖ is the absolute value of the difference between λ and the nearest integer. Let X represent the m-tuple (x1, x2, … xm) and letbe any n linear forms in m variables, where the Θij are real numbers. The following is a classical result of Khintchine (1):For all pairs of positive integers m, n there is a positive constant Г(m, n) with the property that for any forms Lj(X) there exist real numbers α1, α2, …, αn such thatfor all integers x1, x2, …, xm not all zero.

A Direct Rotatability Criterion for Spherical Four-Bar Linkages

1994 ◽  
Author(s):  
R. Ma ◽  
K. C. Gupta
Keyword(s):  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Absolute Value ◽  
The Difference ◽  
Necessary And Sufficient ◽  
Four Bar Linkage

Abstract The necessary and sufficient conditions for the full input rotatability in a spherical four bar linkage are proved. The direct criterion is: for all twist angles α in the range [0, π], the excess (deficit) of the sum of the frame and input twist angles over (from) π should, in absolute value, be greater than that for the coupler and follower twist angles; the difference between the follower and input twist angles, in absolute value, should be greater than that for the coupler and follower twist angles. Application of the direct criterion to full rotatability of other links are discussed and some variations in the form of the criterion are developed.

Performance Analysis of Different Modulation Formats in Optical Communication

2016 ◽  
Vol 37 (2) ◽  
Author(s):  
Kulwinder Singh ◽  
Maninder Singh ◽  
Kamaljit Singh Bhatia ◽  
Hardeep Singh Ryait
Keyword(s):  
Performance Analysis ◽  
Phase Shift ◽  
Resonant Frequency ◽  
Optical Communication ◽  
Data Transmission ◽  
Modulation Formats ◽  
Differential Phase Shift ◽  
Eye Diagram ◽  
The Difference ◽  
Sequence Generator

AbstractIn this paper, we demonstrated the variation of different parameters with quadrature amplitude modulation (QAM) and differential phase shift key (DPSK) sequence generator, which generates modulated signals, in data transmission for communication and analysed that how the difference of these sequence generators effect its resonant frequency (RF) value, eye diagram and electrical constellation representation of the system.

scholarly journals Integrated optical isolators using electrically driven acoustic waves

2020 ◽  
Vol 28 (24) ◽  
pp. 36055
Author(s):  
Nathan Dostart ◽  
Yossef Ehrlichman ◽  
Cale Gentry ◽  
Miloš A. Popović
Keyword(s):  
Acoustic Waves ◽  
Integrated Optical ◽  
Optical Isolators

scholarly journals The Empirical Evaluation of the Determinants of Industrial Manufacturing in the CEMAC Zone

2019 ◽  
Vol 10 (1) ◽  
pp. 72
Author(s):  
Louis Bernard Tchekoumi ◽  
Patrick Danel Nya
Keyword(s):  
Manufacturing Sector ◽  
Empirical Evaluation ◽  
Value Added ◽  
Business Climate ◽  
Geographic Proximity ◽  
Per Capita Gdp ◽  
Absolute Value ◽  
Industrial Manufacturing ◽  
Per Capita ◽  
The Difference

The aim of this article is to assess the determinants of industrial manufacturing in the CEMAC zone. To achieve this, we make use of a gravity model on a static panel with random effects, according to the methodology proposed by Hausman-Taylor. The results show that the population, value added of the manufacturing sector, colonial links and geographic proximity have significant impacts with the expected signs. On the other hand, the difference in absolute value of per capita GDP, the business climate, financial inflows as well as actual distance are the group variables that arise as constraints to export manufacturing.

scholarly journals The Robust Consensus of a Noisy Deffuant-Weisbuch Model

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Jiangbo Zhang ◽  
Yiyi Zhao
Keyword(s):  
Discrete Time ◽  
Model Parameters ◽  
Positive Probability ◽  
Noise Strength ◽  
Opinion Formation ◽  
Time Step ◽  
Absolute Value ◽  
The Difference ◽  
Robust Consensus

We construct a new opinion formation of the Deffuant-Weisbuch model with the interference of the outer noise, where there are finite n agents and the evolution is discrete-time. The opinion interaction occurs by one randomly chosen pair at each time step. The difference to the original Deffuant-Weisbuch model is that communications of any selected pairs will be affected by noises. The aim of this paper is to study the robust consensus of this noisy Deffuant-Weisbuch model. We first define the noise strength as the maximum noise absolute value. We will then show that when the noise strength is less than a certain threshold, this noisy model will achieve T-robust consensus when t is sufficiently large; next we prove that the noisy model achieves robust consensus with a positive probability; finally, we demonstrate these results and provide numerical relations among the noise strength and some model parameters.

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