Coupling efficiency of starlight to low-order-mode optical fibers using adaptive optics: rationale and experiments using the Wavefront Control Experiment

1994 ◽  
Author(s):  
Edward J. Kibblewhite ◽  
Fang Shi ◽  
Walter J. Wild
Keyword(s):  
Adaptive Optics ◽  
Optical Fibers ◽  
Control Experiment ◽  
Coupling Efficiency ◽  
Order Mode ◽  
Wavefront Control ◽  
Low Order

Low-order mode correction anisoplanatism limitations for adaptive optics system

2003 ◽  
Vol 42 (8) ◽  
pp. 2190 ◽  
Author(s):  
Hongtao Zhang ◽  
Fuchang Yin ◽  
Bing Xu ◽  
Wenhan Jiang
Keyword(s):  
Adaptive Optics ◽  
Order Mode ◽  
Adaptive Optics System ◽  
Low Order

scholarly journals Modeling low order aberrations in laser guide star adaptive optics systems

2007 ◽  
Vol 15 (8) ◽  
pp. 4711 ◽  
Author(s):  
Richard M. Clare ◽  
Marcos A. van Dam ◽  
Antonin H. Bouchez
Keyword(s):  
Adaptive Optics ◽  
Laser Guide Star ◽  
Guide Star ◽  
Laser Guide ◽  
Low Order

Fabrication of Lensed Plastic Optical Fiber Array Using Electrostatic Force

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Yih-Tun Tseng ◽  
Jhong-Bin Huang ◽  
Che-Hsin Lin ◽  
Chin-Lung Chen ◽  
Wood-Hi Cheng
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Electrostatic Force ◽  
Coupling Efficiency ◽  
Numerical Aperture ◽  
Uv Curing ◽  
Power Budget ◽  
Fiber Array ◽  
Plastic Optical Fibers ◽  
Efficient Coupling

The GI (graded-index) POFs (Plastic optical fibers), which has been proven to reach distances as long as 1 km at 1.25 Gb/s has a relatively low numerical aperture . Therefore, the efficient coupling of GI POFs to the light source has become critical to the power budget in the system. Efficient coupling for a POFs system normally involves either a separate lens or the direct formation of the lens at the end of the fiber. Forming the lens-like structure directly on the fiber end is preferred for simplicity of fabrication and packaging, such as polishing and fusion, combine different fibers with the cascaded fiber method and hydroflouride (HF) chemical etching. These approaches are well established, but applicable only to glass. Optical assembly architecture for multichannel fibers and optical devices is critical to optical fiber interconnections. Multichannel fiber-pigtail laser diode (LD) modules have potential for supporting higher data throughput and longer transmission distances. However, to be of practical use, these modules must be more precise. This work proposes and manufactures lensed plastic optical fibers (LPOF) array. This novel manipulation can be utilized to fabricate an aspherical lens on a fiber array after the UV curing of the photo-sensitive polymer; the coupling efficiency (CE) is increased and exceeds 47% between the LD array and the fiber array.

Development of a low-order Adaptive Optics system at Udaipur Solar Observatory

2008 ◽  
Vol 29 (1-2) ◽  
pp. 353-357 ◽  
Author(s):  
A. R. Bayanna ◽  
B. Kumar ◽  
R. E. Louis ◽  
P. Venkatakrishnan ◽  
S. K. Mathew
Keyword(s):  
Adaptive Optics ◽  
Solar Observatory ◽  
Adaptive Optics System ◽  
Low Order

FPGA-accelerated adaptive optics wavefront control

2014 ◽  
Author(s):  
S. Mauch ◽  
J. Reger ◽  
C. Reinlein ◽  
M. Appelfelder ◽  
M. Goy ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Wavefront Control

Real time controller for 37-element low-order solar adaptive optics system at 1m new vacuum solar telescope

2012 ◽  
Author(s):  
Lei Zhu ◽  
Naiting Gu ◽  
Shanqiu Chen ◽  
Lanqiang Zhang ◽  
Xiaoyun Wang ◽  
...  
Keyword(s):  
Real Time ◽  
Adaptive Optics ◽  
Solar Telescope ◽  
Adaptive Optics System ◽  
Low Order

scholarly journals High-order mode suppression in double-clad optical fibers by adding absorbing inclusions

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Svetlana S. Aleshkina ◽  
Tatiana A. Kochergina ◽  
Vladimir V. Velmiskin ◽  
Konstantin K. Bobkov ◽  
Mikhail M. Bubnov ◽  
...  
Keyword(s):  
Optical Fibers ◽  
High Order Mode ◽  
High Order ◽  
Order Mode ◽  
Mode Suppression

scholarly journals On-sky results for adaptive optics control with data-driven models on low-order modes

2020 ◽  
Vol 498 (3) ◽  
pp. 3228-3240
Author(s):  
Baptiste Sinquin ◽  
Léonard Prengère ◽  
Caroline Kulcsár ◽  
Henri-François Raynaud ◽  
Eric Gendron ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
High Performance ◽  
Temporal Dynamics ◽  
Data Driven ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Integral Action ◽  
High Performance Systems ◽  
Performance Results ◽  
Low Order

ABSTRACT Dedicated tip–tilt loops are commonly implemented on adaptive optics (AO) systems. In addition, a number of recent high-performance systems feature tip–tilt controllers that are more efficient than the integral action controller. In this context, linear–quadratic–Gaussian (LQG) tip–tilt regulators based on stochastic models identified from AO telemetry have demonstrated their capacity to effectively compensate for the cumulated effects of atmospheric disturbance, windshake and vibrations. These tip–tilt LQG regulators can also be periodically retuned during AO operations, thus allowing to track changes in the disturbances’ temporal dynamics. This paper investigates the potential benefit of extending the number of low-order modes to be controlled using models identified from AO telemetry. The global stochastic dynamical model of a chosen number of turbulent low-order modes is identified through data-driven modelling from wavefront sensor measurements. The remaining higher modes are modelled using priors with autoregressive models of order 2. The loop is then globally controlled using the optimal LQG regulator build from all these models. Our control strategy allows for combining a dedicated tip–tilt loop with a deformable mirror that corrects for the remaining low-order modes and for the higher orders altogether, without resorting to mode decoupling. Performance results are obtained through evaluation of the Strehl ratio computed on H-band images from the scientific camera, or in replay mode using on-sky AO telemetry recorded in 2019 July on the CANARY instrument.

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