Analysis of Influence of Beam Expender Parameters on Coupling Efficiency of Single Mode Fiber Used in Lidar

2013 ◽  
Vol 552 ◽  
pp. 339-344 ◽  
Author(s):  
Hong Jiang Sheng ◽  
Jian Dong Mao ◽  
Xue Sheng Li
Keyword(s):  
Coupling Efficiency ◽  
Single Mode ◽  
Spot Size ◽  
Single Mode Fiber ◽  
Propagation Theory ◽  
Laser Propagation ◽  
Theoretical Function ◽  
Spot Radius ◽  
Numerical Computing ◽  
The Relationship

Based on theoretical analysis, the beam expender used in all fiber lidar with a coupling efficiency of single mode fiber (SMF) is investigated. Some numerical computations are carried out and following results are obtained. For all fiber lidar in order to get the maximum coupling efficiency on SMF, the relationship between the distance d, ranged from the secondary to primary lens of the beam expender, and the laser waist spot location l, which is at a distance from the secondary lens of beam expender are obtained. And also the relationship between l and the measurable bandwidth is analyzed. Under the condition that if the laser location is certain and the imagine spot location is infinite, with adjusting the distance d which can make the image spot size obtain its minimum, the maximum coupling efficiency about 70.6% is got and the adjusting range of d has only 0.2~0.9mm. Assuming that the image spot distance is infinite, and the minimum of spot radius is got after the laser waist spot goes through the beam expender, the function between d and l is retrieved by use of laser propagation theory. By comparing the theoretical curve with the computing one, the theoretical function agrees with the numerical computing curve approximately. These conclusions have the important directive significance for design of all fiber Lidar.

Coupling efficiency of non-uniformly correlated beams into a single-mode fiber in turbulence (Invited)

2020 ◽  
Vol 49 (12) ◽  
pp. 20201049-20201049
Author(s):  
蔺淑琴 Shuqin Lin ◽  
张继前 Jiqian Zhang ◽  
朱新蕾 Xinlei Zhu ◽  
王飞 Fei Wang ◽  
蔡阳健 Yangjian Cai ◽  
...  
Keyword(s):  
Coupling Efficiency ◽  
Single Mode ◽  
Single Mode Fiber

Fabrication, Characterization and Microsensing of Whispering-Gallery Mode Micro-Coupling Systems

2008 ◽  
Author(s):  
Qiulin Ma ◽  
Tobias Rossmann ◽  
Zhixiong Guo
Keyword(s):  
Transmission Loss ◽  
Coupling Efficiency ◽  
High Sensitivity ◽  
Single Mode ◽  
Whispering Gallery Mode ◽  
Single Mode Fiber ◽  
Whispering Gallery ◽  
Coupling System ◽  
Wide Range ◽  
Micro Sensor

An optical micro-coupling system of whispering-gallery mode usually consists of a resonator (e.g. a sphere) and a coupler (e.g. a taper). In this report, silica microspheres of 50–500 μm in diameter are fabricated by hydrogen flame fusing of an end of a single mode fiber or fiber taper. Fiber tapers are fabricated by the method of heating and pulling that meets an adiabatic condition. Taper’s waist diameter can routinely be made less than 1 μm and almost zero transmission loss in a taper is achieved which allows an effective and phase-matched coupling for a wide range sizes of microspheres. Both resonators and couplers’ surface microstructure and shapes are examined by scanning electronic microscopy. Three regimes of coupling are achieved, enabling a good flexibility to control Q value and coupling efficiency of a micro-coupling system. Whispering gallery mode shift is used to demonstrate a novel temperature micro-sensor. Its sensitivity determined from actual experimental results agrees well with the theoretical value. A concept of using the photon’s cavity ring down (CRD) in the microsphere to make a novel high-sensitivity trace gas micro-sensor is proposed. The CRD time constant when ammonia is chosen as the analyte gas is predicted using the simulated absorption lines.

Coupling efficiency of single-mode fiber components using GRIN-rod lenses

1988 ◽  
Vol 7 (2) ◽  
pp. 85-107 ◽  
Author(s):  
Yiqun Lu ◽  
Joseph C. Palais ◽  
Yue Chen
Keyword(s):  
Coupling Efficiency ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Fiber Components

Quantum well electron transfer waveguide with high coupling efficiency to single-mode fiber

1995 ◽  
Vol 7 (2) ◽  
pp. 194-196 ◽  
Author(s):  
H.N. Khan ◽  
J.E. Zucker ◽  
T.Y. Chang ◽  
N.J. Sauer ◽  
C.A. Burrus ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Quantum Well ◽  
Coupling Efficiency ◽  
Single Mode ◽  
Single Mode Fiber

Coupling Efficiency And Sensitivity Of An Edge-Emitting Led To Single-Mode Fiber

1987 ◽  
Author(s):  
L. A. Reith ◽  
D. N. Christodoulides ◽  
M. A. Saifi ◽  
P. W. Shumate
Keyword(s):  
Coupling Efficiency ◽  
Single Mode ◽  
Single Mode Fiber

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.

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