Research On The Method Of Calculating Laser Spot Center

Laser technology has developed rapidly ever since the first Ruby Laser was invested by Maiman in 1960. Laser, as a light wave, has no difference in nature from other common waves. Yet as far as radiation mechanism, there is far different between them and laser has a few unparalleled traits that can not be found in other common light waves. Possessed with good qualities of monochromaticity and direction, laser has a wide application in non-contact measurement. However, laser beams, having certain quality of radiation caused by the laser output of flat-surface wave of limited breath and the effect of diffraction, may cause unequally distributed energy and changed shape of laser spot.During the measuring process when a laser light source forms image through optical system, laser spot is likely to be deformed and the focus also definitely out of the regular point, because of the aberration in the optical system. Based on this, this thesis mainly research on some relevant traits of laser spot, establish the connection between Zernike coefficient an the traditional Seidel aberration coefficient by gathering image information of laser spot in the optical system and making use of Zernike polynomial in the fitting of wave surface, and thus judge the shape and characteristics of spot and to what extant that aberration will have an effect on the spot, base on coma calculation, then it goes further to calculate and adjust the laser spot center and get to tall measurement precision.