Research On Laser Energy Distribution Based On Image Processing

In the space optical communications, laser beam transmission is impacted by the atmospheric turbulence and atmospheric extinction. The laser energy density distribution and attenuation in space optical communication are provided by the research on the laser spot on the receiving end by using image processing methods qualitatively and quantitatively.In order to realize measurement and analysis of laser energy density distribution, the laser spot is processed based on image processing, and its applied algorithms such as laser spot identification, processing, wavefront fitting and 3-D pseudo-color visualization are investigated. First, the spot images gained from image grabbing card are identified and pretreated. Then wavefront is fitted based on Zernike polynomial, and fitting sample points number and selection is studied. Finally, 3-D pseudo-color visualization algorithm is used for 2-D laser spot images. Experimental results indicate that the Zernike polynomial fitting realized wavefront detection and reconstruction. Concentric and actinomorphic sample distribution makes the experiment average error of laser energy density testing precision least. The visualization method reflects the relative sizes and positions of laser spot energy distribution in different areas. One can conveniently observe the energy distribution of laser spot from different angles through 3-D coordinate transform. It can satisfy the system requirements of non-contact, online, real time, higher precision and rapid speed, as well as strong anti-jamming and stabilization.The soft system basically satisfied the demand of laser energy density measurement and it provides an important basis for evaluating beam quality.