scholarly journals Experimental Research on Automatic Alignment and Control Algorithm of Spatial Light-Fiber Coupling

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xizheng Ke ◽  
Benkang Yin
Keyword(s):  
Piezoelectric Ceramic ◽  
Low Cost ◽  
Coupling Efficiency ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Ceramic Fiber ◽  
Free Space Optical ◽  
Fiber Coupler ◽  
Automatic Alignment ◽  
Space Optical Communication

This study aims to solve the difficulties in the coupling between space light and single-mode fiber (SMF) in free-space optical communication. A fiber coupler based on two-dimensional (2D) piezoelectric ceramics was developed, which uses the stochastic parallel gradient descent (SPGD) algorithm to realize the automatic coupling of space light-SMF. In addition, a spatial light-SMF alignment experimentation platform was built indoors to verify the effectiveness and practicality of the 2D piezoelectric ceramic fiber coupler. The results show that the use of the SPGD algorithm can realize the automatic alignment of fiber position coupling, and the SMF coupling efficiency reaches 52.58% when the system is closed loop. 2D piezoelectric ceramic fiber couplers have unique advantages of low cost, simplified structure, and easy array expansion and can effectively solve the difficulty in the alignment of spatial light-SMF coupling. This study will serve as a significant reference for the research on spatial fiber-coupled array technology.

Free-space to single-mode fiber coupling efficiency with optical system aberration and fiber positioning error under atmospheric turbulence

2021 ◽  
Author(s):  
Yiming Bian ◽  
Yan Li ◽  
Erhu Chen ◽  
Wei Li ◽  
Xiaobin Hong ◽  
...  
Keyword(s):  
Atmospheric Turbulence ◽  
Optical System ◽  
Free Space ◽  
Fiber Optic ◽  
Coupling Efficiency ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Positioning Error ◽  
Free Space Optical ◽  
Statistical Expectation

Abstract Benefiting from the rapid development of fiber-optic devices, high-speed free-space optical communication systems have recently used fiber-optic components. The received laser beam in such a system couples into single-mode fiber (SMF) at the input of the receiver module. This work is oriented to common problems in actual free-space optical coupling systems, such as atmospheric turbulence, optical system aberration, and fiber positioning error. We derive the statistical expectation models of SMF coupling efficiency with optical system aberration in the presence of atmospheric turbulence and the statistical expectation models of SMF coupling efficiency with fiber positioning error in the presence of atmospheric turbulence. The influences of optical system aberration and fiber positioning error on the coupling efficiency under different turbulence strengths are also analyzed in this paper.

scholarly journals Coupling Characteristics of Fused Optical Fiber Coupler Formed with Single-Mode Fiber and Photonic Crystal Fiber Having Air Hole Collapsed Taper

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Hirohisa Yokota ◽  
Hirotomo Yashima ◽  
Yoh Imai ◽  
Yutaka Sasaki
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Extinction Ratio ◽  
Coupling Efficiency ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Fiber Coupler ◽  
Crystal Fiber ◽  
Coupling Characteristics ◽  
Air Hole

Fused coupler forming with a single-mode fiber (SMF) and a photonic crystal fiber (PCF) is one of the solutions for optical coupling from a light source to a PCF. In this paper, we presented coupling characteristics of a fused fiber coupler formed with an ordinary SMF and a PCF having air hole collapsed taper. A prototype of SMF-PCF coupler with air hole collapsed taper was fabricated using CO2 laser irradiation. The coupling efficiency from SMF to PCF was −6.2 dB at 1554 nm wavelength in the fabricated coupler. The structure of the SMF-PCF coupler to obtain high coupling efficiency was theoretically clarified by beam propagation analysis using an equivalent model of the coupler with simplification. It was clarified that appropriately choosing the prestretched or etched SMF diameter and the length of air hole collapsed region was effective to obtain high coupling efficiency that was a result of high extinction ratio at cross port and low excess loss. We also demonstrated that the diameter of prestretched SMF to obtain high coupling efficiency was insensitive to the air hole diameter ratio to pitch of the PCF in the air hole collapsed SMF-PCF coupler.

Co-Axial, Double Waveguide Single-Mode Fiber Coupler

1987 ◽  
Author(s):  
S. Tammela ◽  
H. von Bagh ◽  
S. Honkanen ◽  
M. Leppihalme
Keyword(s):  
Single Mode ◽  
Single Mode Fiber ◽  
Fiber Coupler

Switchable and tunable linear cavity erbium-doped fiber laser based on FBGs embedded in Sagnac rings

Laser Physics ◽  
2021 ◽  
Vol 32 (1) ◽  
pp. 015101
Author(s):  
Gangxiao Yan ◽  
Weihua Zhang ◽  
Peng Li ◽  
Qiuhao Jiang ◽  
Meng Wu ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Low Cost ◽  
Single Mode ◽  
Optical Signal ◽  
Single Mode Fiber ◽  
Hole Burning ◽  
Linear Cavity ◽  
Erbium Doped ◽  
Optical Fiber Sensing ◽  
Birefringence Effect

Abstract A switchable and tunable erbium-doped fiber laser with a linear cavity based on fiber Bragg gratings embedded in Sagnac rings is proposed and experimentally verified. Due to the stress birefringence effect and the polarized hole burning effect, which are introduced into the single-mode fiber in the polarization controllers (PCs) by the PCs, the designed laser can achieve seven kinds of laser-states output including three kinds of single-wavelength laser states, three kinds of dual-wavelength laser states and one kind of triple-wavelength laser state. The optical signal-to-noise ratios of the output wavelengths are all higher than 52 dB, and the wavelength shifts are all less than 0.04 nm. Furthermore, the temperature tuning of the wavelength range is also researched, which is about 1.2 nm. Due to advantages, such as low cost, simple structure, easy switching and multiple laser states, the designed laser has great application potential in laser radar, optical fiber sensing and so on.

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