The beam pointing is the most crucial issue for beam combining to achieve high energy laser output. In order to meet the turbulence situation, a beam pointing method that cooperates with the stochastic parallel gradient descent (SPGD) algorithm is propose
A design and testing of a cost-effective distributed optical remote sensing methane system, which will help one to detect gas leaks from multi-coal face in mines simultaneously, is presented. The fundamentals of the remote detection are based on frequency