Coherent beam combination of two slab laser amplifiers based on stochastic parallel gradient descent algorithm

• 来源期刊: 中国光学快报（英文版）
• 年，卷（期）: 2011,（11）
• 页码范围: 48-50
• 页数: 3页
• 语种: 英文
• DOI: 10.3788/COL201109.101401

摘要

Coherent beam combination (CBC) of laser arrays is an efficient way to scale brightness.We demonstrate CBC of two slab laser amplifiers based on active phase locking.Instead of the complex phase detection system,intensity detection is used and the feedback control signal is calculated based on the stochastic parallel gradient descent (SPGD) algorithm.The experimental investigation on a 101.5-W CBC of two slab amplifiers shows that the entire system in a closed loop performs well for long-time observation.A combination efficiency of nearly 81％ is realized.The slab amplifier laser arrays are the coherent beams efficiently combined by active phase locking based on the SPGD.Coherent beam combination (CBC) of laser arrays has potential applications in laser radar and energy delivering systems[1].Two categories of CBC are passive phasing in a master oscillator and active phasing using power amplifier configuration[2-9].Most studies on CBC are based on fiber lasers because of their inherently compact size and high beam quality.In 2009,Northrop Grumman Corporation (NGC) unveiled their 100-kW system based on slab laser amplifiers with heterodync phase detecting technology[10].To date,this system remains an excellent example of the highest power demonstrations of CBC.