Multimode fiber laser beam cleanup based on stochastic parallel gradient descent algorithm

• Published in: Optics communications Vol. 284; no. 2; pp. 613 - 615
• Main Authors: Zhao, Hai-Chuan, Ma, Hao-Tong, Zhou, Pu, Wang, Xiao-Lin, Ma, Yan-Xing, Li, Xiao, Xu, Xiao-Jun, Zhao, Yi-Jun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.2011; Elsevier
• Subjects: Algorithms; Beam cleanup; Beams (radiation); Cleaning; Descent; Display devices, liquid-crystal devices; Exact sciences and technology; Fiber lasers; Fundamental areas of phenomenology (including applications); Lasers; Multimode fiber laser; Optical elements, devices, and systems; Optical processors, correlators, and modulators; Optics; Physics; Spatial light modulators; Stochastic parallel gradient descent; Stochasticity; Wavelengths; Spatial light modulators; Multimode fiber laser; Beam cleanup; Stochastic parallel gradient descent; Optical fibers; Multimode laser; Multimode fibers; Single mode fiber; Laser beams; Algorithms; Liquid crystal devices; Adaptive optics; Fiber lasers
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2010.09.039

We present experimental research on multimode fiber laser beam cleanup based on a stochastic parallel gradient descent (SPGD) algorithm. The multimode laser is obtained by injecting a 1064 nm central wavelength single mode fiber laser into a multimode fiber and the system is setup by using phase only liquid crystal spatial light modulators (LC-SLM). The quality evaluation function is increased by a factor of 10.5 and 65% of the laser energy is encircled in the central lobe when the system evolves from open-loop into close-loop state. Experimental results indicate the feasibility of the multimode fiber laser beam cleanup by adaptive optics (AO).