High-isolation polarization-independent optical circulator coupled with single-mode fibers

1991 ◽  
Vol 9 (4) ◽  
pp. 456-460 ◽  
Author(s):  
Y. Fujii
Keyword(s):  
Single Mode ◽  
High Isolation ◽  
Optical Circulator ◽  
Polarization Independent

scholarly journals Polarization-Independent Circulator Based on Composite Rod of Ferrite and Plasma in Photonic Crystal Structure

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 381
Author(s):  
Mi Lin ◽  
Lixin Fu ◽  
Shakeel Ahmed ◽  
Qiong Wang ◽  
Yaoxian Zheng ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Large Scale ◽  
Optimization Method ◽  
Coupling Condition ◽  
High Isolation ◽  
Optimum Parameters ◽  
Composite Rod ◽  
Polarized Waves ◽  
Two Dimensional Photonic Crystal ◽  
Polarization Independent

We propose a type of polarization-independent circulator based on a composite rod of ferrite and plasma materials in a two-dimensional photonic crystal (PhC) slab. Only one composite rod was set at the center of the structure to provide circulation for both TE- and TM-polarized waves. Additionally, to improve the performance of the circulator, three additional rods were inserted to improve the coupling condition between the center magneto-optical microcavity and the corresponding waveguides. Finite element method was used to calculate the characteristics of the structure and the Nelder–Mead optimization method was employed to obtain the optimum parameters. The results show that a low insertion loss (~0.22 dB) and high isolation (~14 dB) can be achieved in our structure for waves of both TE and TM polarizations. The idea presented here may be useful for designing compact polarization devices in large-scale integrated photonic circuits.

Distributed acoustic sensing of subsea wells

2020 ◽  
Vol 39 (11) ◽  
pp. 801-807
Author(s):  
Andreas Ellmauthaler ◽  
Brian C. Seabrook ◽  
Glenn A. Wilson ◽  
John Maida ◽  
Jeff Bush ◽  
...  
Keyword(s):  
Single Mode ◽  
Field Trials ◽  
Single Mode Fiber ◽  
Optical Losses ◽  
Acoustic Sensing ◽  
Well Integrity ◽  
Sand Control ◽  
Processing Algorithms ◽  
Distributed Acoustic Sensing ◽  
Optical Circulator

Topside distributed acoustic sensing (DAS) of subsea wells requires advanced optical engineering solutions to compensate for reduced acoustic bandwidth, optical losses, and back reflections that are accumulated through umbilicals, multiple wet- and dry-mate optical connectors, splices, optical feedthrough systems, and downhole fibers. To address these issues, we introduce a novel DAS solution based on subsea fiber topology consisting of two transmission fibers from topside and an optical circulator deployed in the optical flying lead at the subsea tree. This solution limits the sensing fiber portion to the downhole fiber, located below the subsea tree, and enables dry-tree-equivalent acoustic sampling frequencies of more than 10 kHz while eliminating all back reflections from multiple subsea connectors above the tree. When combined with enhanced backscatter single-mode fiber, this gives rise to a DAS interrogation system that is capable of providing dry-tree-equivalent acoustic sensing performance over the entire length of the subsea well, regardless of the tie-back distance. It also enables the same spectral-based DAS processing algorithms developed for seismic, sand control, injector/producer profiling, and well integrity on dry-tree wells to be applied directly to subsea DAS data. The performance of this subsea DAS system has been validated through a series of laboratory and field trials. We show the results of the tests and discuss how the system is deployed within subsea infrastructure.

Polarization-independent single-mode rib waveguides on silicon-on-insulator for telecommunication wavelengths

2002 ◽  
Vol 210 (1-2) ◽  
pp. 43-49 ◽  
Author(s):  
L Vivien ◽  
S Laval ◽  
B Dumont ◽  
S Lardenois ◽  
A Koster ◽  
...  
Keyword(s):  
Single Mode ◽  
Silicon On Insulator ◽  
Rib Waveguides ◽  
Polarization Independent

Waveguide polarization-independent optical circulator

1999 ◽  
Vol 11 (3) ◽  
pp. 355-357 ◽  
Author(s):  
N. Sugimoto ◽  
T. Shintaku ◽  
A. Tate ◽  
H. Terui ◽  
M. Shimokozono ◽  
...  
Keyword(s):  
Optical Circulator ◽  
Polarization Independent
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