Generation of dark hollow beam via coherent combination based on adaptive optics.

A novel method for generating a dark hollow beam (DHB) is proposed and studied both theoretically and experimentally. A coherent combination technique for laser arrays is implemented based on adaptive optics (AO). A beam arraying structure and an active segmented mirror are designed and described. Piston errors are extracted by a zero-order interference detection system with the help of a custom-made photo-detectors array. An algorithm called the extremum approach is adopted to calculate feedback control signals. A dynamic piston error is imported by LiNbO3 to test the capability of the AO servo. In a closed loop the stable and clear DHB is obtained. The experimental results confirm the feasibility of the concept.

[1]  Mikhail A. Vorontsov,et al.  Adaptive phase-locked fiber array with wavefront phase tip-tilt compensation using piezoelectric fiber positioners , 2007, SPIE Optical Engineering + Applications.

[2]  Lixin Xu,et al.  Flat-top laser beam generated by coherent beam combining of Gaussian lasers , 2010 .

[3]  Wolfgang M. Neubert,et al.  Experimental demonstration of an optical phased array antenna for laser space communications. , 1994, Applied optics.

[4]  Grover A. Swartzlander,et al.  Trapping of low-index microparticles in an optical vortex , 1998 .

[5]  Pu Zhou,et al.  Coherent beam combining of two W-level fiber amplifiers in turbulence atmospheric environment based on stochastic parallel gradient descent algorithm , 2009 .

[6]  Greg Gbur,et al.  Vortex beam propagation through atmospheric turbulence and topological charge conservation. , 2008, Journal of the Optical Society of America. A, Optics, image science, and vision.

[7]  Hans W. Bruesselbach,et al.  Power-scalable phase-compensating fiber-array transceiver for laser communications through the atmosphere , 2005 .

[8]  Zhaoying Wang,et al.  Atomic trapping and guiding by quasi-dark hollow beams , 2005 .

[9]  B. Lü,et al.  Beam propagation properties of radial laser arrays. , 2000, Journal of the Optical Society of America. A, Optics, image science, and vision.

[10]  Shutian Liu,et al.  Generation of hollow Gaussian beam by phase-only filtering. , 2008, Optics express.

[11]  S. A. Collins.  Lens-System Diffraction Integral Written in Terms of Matrix Optics , 1970 .

[12]  Composite coherence vortices in a radial beam array propagating through atmospheric turbulence along a slant path , 2010 .

[13]  T. Fan,et al.  Coherent beam combining and phase noise measurements of ytterbium fiber amplifiers. , 2004, Optics letters.

[14]  H Komine,et al.  Coherent combination of high-power, zigzag slab lasers. , 2006, Optics letters.

[15]  Shi-Yao Zhu,et al.  Formation of optical vortices using coherent laser beam arrays , 2009 .

[16]  I Itzkan,et al.  Optical beam shaping of a high power laser for uniform target illumination. , 1985, Applied optics.

[17]  Kishan Dholakia,et al.  The Production Of Multiringed Laguerre-Gaussian Modes By Computer-Generated Holograms , 1998 .

[18]  J. Hou,et al.  Coherent combining technology of master oscillator power amplifier fiber arrays. , 2008, Optics express.

[19]  Jianping Yin,et al.  Atom guiding and cooling by a dark hollow laser beam , 1998 .

[20]  H. Fujiwara,et al.  High-energy flat-top beams for laser launching using a Gaussian mirror. , 2010, Applied optics.

[21]  Generation of hollow beams by spiral rays in multimode light guides. , 2010, Optics express.

[22]  M. Shao,et al.  Atmospheric phase measurements with the Mark III stellar interferometer. , 1987, Applied optics.

[23]  Mingwu Ao,et al.  A strip extracting algorithm for phase noise measurement and coherent beam combining of fiber amplifiers , 2010 .

[24]  Yoshio Hayasaki,et al.  Motion control of low-index microspheres in liquid based on optical repulsive force of a focused beam array. , 2009, Optics letters.

[25]  Mikhail A. Vorontsov,et al.  Development of adaptive fiber collimators for conformal fiber-based beam projection systems , 2008, Optical Engineering + Applications.