Integrated Nonreciprocal Devices for Application in Optical Communication Systems

1998 ◽  
Vol 517 ◽  
Author(s):  
T. Shintaku ◽  
N. Sugimoto ◽  
A. Tate ◽  
E. Kubota ◽  
H. Kozawaguchi ◽  
...  
Keyword(s):  
Communication Systems ◽  
Beam Splitter ◽  
Mode Conversion ◽  
Single Mode ◽  
Mode Wave ◽  
Tm Mode ◽  
Optical Communication Systems ◽  
Optic Waveguide ◽  
Optical Circulator ◽  
Iron Garnet

AbstractWe describe our recently developed integrated isolators. Their structure is simple, in that it consists solely of a single-mode channel magneto-optic waveguide. The operating principle is that a backward fundamental TM mode wave is converted to higher-order or radiation TE modes while a forward fundamental TM mode wave propagates with no mode conversion. These isolators are realized using a single-mode rib channel waveguide in Ce-substituted yttrium iron garnet which has a very large Faraday rotation. We obtain 13-27 dB isolation around a wavelength of 1.55 μm. We also review our recent study on a hybrid-integrated polarization-independent optical circulator based on a nonreciprocal Mach-Zehnder interferometer which does not need a polarization-beam splitter. We obtain 14.1-23.7 dB isolation at λ = 1.55 μm.

scholarly journals Magnetless Optical Circulator Based on an Iron Garnet with Reduced Magnetization Saturation

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4692
Author(s):  
Gianni Portela ◽  
Miguel Levy ◽  
Hugo E. Hernandez-Figueroa
Keyword(s):  
Optical Communication ◽  
Communication Systems ◽  
Three Dimensional ◽  
Optical Material ◽  
Molecular Formula ◽  
Magnetic Domains ◽  
Reduced Dimensions ◽  
Optical Communication Systems ◽  
Optical Circulator ◽  
Iron Garnet

A three-port circulator for optical communication systems comprising a photonic crystal slab made of a magneto-optical material in which an magnetizing element is not required to keep its magnetic domains aligned is suggested for the first time. By maximizing the incorporation of europium to its molecular formula, the magneto-optical material can remain in the saturated magnetic state even in the absence of an external DC magnetic field. Two- and three-dimensional simulations of the device performed with full-wave electromagnetic solvers based on the finite element method demonstrate that, at the 1550 nm wavelength, the insertion loss, isolation, and reflection levels are equal to or better than −1 dB, −14 dB, and −20 dB, respectively. Since its operation does not require an electromagnet or a permanent magnet, the suggested circulator is much more compact, being able to reach footprints in the range of three orders of magnitude smaller, when compared to other circulator designs referred to in the literature and the presented results can be useful for the design of other nonreciprocal devices with reduced dimensions for optical communication systems.

scholarly journals Correlation and Power Distribution of Intercore Crosstalk Field Components of Polarization-Coupled Weakly Coupled Single-Mode Multicore Fibres

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 191
Author(s):  
José A. P. Morgado ◽  
Adolfo V. T. Cartaxo
Keyword(s):  
Power Distribution ◽  
Communication Systems ◽  
Single Mode ◽  
Coupled Mode ◽  
Weakly Coupled ◽  
Wide Range ◽  
Optical Communication Systems ◽  
The Mean ◽  
Distribution Of Power ◽  
Linear Propagation

The correlation and power distribution of intercore crosstalk (ICXT) field components of weakly coupled multicore fibers (WC-MCFs) are important properties that determine the statistics of the ICXT and ultimately impact the performance of WC-MCF optical communication systems. Using intensive numerical simulation of the coupled mode equations describing ICXT of a single-mode WC-MCF with intracore birefringence and linear propagation, we assess the mean, correlation, and power distribution of the four ICXT field components of unmodulated polarization-coupled homogeneous and quasi-homogeneous WC-MCFs with a single interfering core in a wide range of birefringence conditions and power distribution among the field components at the interfering core input. It is shown that, for homogeneous and quasi-homogeneous WC-MCFs, zero mean uncorrelated ICXT field components with similar power levels are observed for birefringence correlation length and birefringence beat length in the ranges of 0.5m,10m and 0.1m,10m, respectively, regardless of the distribution of power between the four field components at the interfering core input.

High-power InGaAsP edge-emitting LEDs for single-mode optical communication systems

1985 ◽  
Vol 21 (17) ◽  
pp. 730 ◽  
Author(s):  
R. Olshansky ◽  
D. Fye ◽  
J. Manning ◽  
M. Stern ◽  
E. Meland ◽  
...  
Keyword(s):  
Optical Communication ◽  
High Power ◽  
Communication Systems ◽  
Single Mode ◽  
Optical Communication Systems

Fabrication Processes of SOI Structure for Optical Nonreciprocal Devices

2018 ◽  
Vol 777 ◽  
pp. 107-112
Author(s):  
Salinee Choowitsakunlert ◽  
Kenji Takagiwa ◽  
Takuya Kobashigawa ◽  
Nariaki Hosoya ◽  
Rardchawadee Silapunt ◽  
...  
Keyword(s):  
Adhesive Bonding ◽  
Mode Conversion ◽  
Silicon On Insulator ◽  
Radiation Mode ◽  
Optical Isolator ◽  
Optic Waveguide ◽  
Iron Garnet ◽  
Relationship Of ◽  
The Relationship ◽  
Magneto Optic

Fabrication processes of a magneto-optic waveguide with a Si guiding layer for an optical isolator employing a nonreciprocal guided-radiation mode conversion are investigated. The optical isolator is constructed on a silicon-on-insulator (SOI) structure. The magneto-optic waveguide is fabricated by bonding the Si guiding layer with a cerium-substituted yttrium iron garnet (Ce:YIG). The relationship of waveguide geometric parameters is determined at a wavelength of 1550 nm. The results show that larger tolerance for isolator operation can be obtained at smaller gaps between Si and Ce:YIG. Bonding processes including photosensitive adhesive bonding and surface activated bonding are then compared. It is found that the surface activated bonding process is easier to control and more promising than the photosensitive adhesive bonding.

Feedback effects in optical communication systems: characteristic curve for single-mode InGaAsP lasers

1992 ◽  
Vol 31 (24) ◽  
pp. 5044 ◽  
Author(s):  
F. Brivio ◽  
C. Reverdito ◽  
G. Sacchi ◽  
G. Chiaretti ◽  
M. Milani
Keyword(s):  
Optical Communication ◽  
Communication Systems ◽  
Characteristic Curve ◽  
Single Mode ◽  
Feedback Effects ◽  
Optical Communication Systems

Feasibility Study of Few Mode Fibers as a Sensor

2018 ◽  
Vol 7 (2) ◽  
pp. 14-30
Author(s):  
Chandana S ◽  
Amulya K L ◽  
Bhavana A M ◽  
Chaithra B ◽  
Chaitra S
Keyword(s):  
Communication Systems ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Physiological Parameters ◽  
Physiological Parameter ◽  
Sensing Element ◽  
Interference Spectrum ◽  
Optical Communication Systems ◽  
Linearly Polarized ◽  
Novel Concept

This article describes how few mode fiber (FMF) has found its applications in optical communication systems. We report a novel concept of sensing physiological parameters using FMF, which utilizes Space Division Multiplexing technology (SDM) where SDM supports multiple modes/ paths of fixed bandwidth channels which increases the data carrying capacity in an optical fiber. Here we have considered two linearly polarized (LP) modes namely LP01 and LP11. A segment of FMF is used as sensing element, where it is spliced between two segments of single mode fiber (SMF). The intermodal interference between LP01 mode and LP11 mode of FMF provides an interference spectrum which is sensitive to change in physiological parameters applied on FMF. Hence any change in physiological parameter results to shift in wavelength in interference spectrum which makes FMF as a sensor

scholarly journals Traffic interception in fiber optical video-systems

2021 ◽  
Vol 2086 (1) ◽  
pp. 012150
Author(s):  
Yu E Krivenko ◽  
E I Andreeva
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Communication Systems ◽  
Wide Spectrum ◽  
Wave Length ◽  
Single Mode ◽  
Additional Noise ◽  
Optical Communication Systems ◽  
Video Systems ◽  
Increased Sensitivity

Abstract In fiber-optic video systems, as well as in optical communication systems, standard single mode optical fibers (SSMF, standard G.652) are usually used. One of the advantages of these fibers is the ability to use CWDM in a wide spectrum. At the same time, more optimal near the wave-length of 1550 nm are provided by non-zero dispersion fiber (NZDSF, standard G.655) fibers. However, as studies have shown, these optical fibers have an increased sensitivity to bending. This fact can be used to traffic interception. It is shown that fiber-optics systems with SSMF have more protection from traffic interception than systems with NZDSF. To transmit a high-confidentiality video signal, special techniques, such as frequency modulation, can be used, or additional noise signals can be added.

Fabricating Lensed Fiber Using a Novel Polishing Method

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Yih-Tun Tseng ◽  
Jhong-Bin Huang ◽  
Wei-Jyun Su
Keyword(s):  
High Power ◽  
Communication Systems ◽  
Coupling Efficiency ◽  
Single Mode ◽  
High Power Laser ◽  
Power Laser ◽  
Long Distance ◽  
Mode Field ◽  
Optical Communication Systems ◽  
Distance Communication

In optical communication systems, 980 nm high-power laser modules are applied for long-distance communication amplifiers. Since the mode field of the 980 nm laser diodes is different from single-mode fibers, coupling losses may occur. In order to improve this problem, lensed fibers have been used widely recently, such as lensed fiber employing quadrangular-pyramid-shaped fiber endface (QPSFE). The QPSFE can easily yield any elliptical microlens aspect ratio to match the far field of the high-power laser diode but the fiber endface must be polished and then spliced during present manufacturing process. It is a time-consuming task and the melting depth of the fiber endface is controlled with difficulty. This study develops a novel fiber endface polishing method for manufacturing the lensed fiber employing QPSFE. Using this new method, the coupling efficiency exceeds 70%.

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