Axisymmetric vector structure characteristics of polarization beam laser cutting machine

Because the axisymmetric polarization beam laser cutting machine has the unique advantages, therefore, studying the characteristics of the vector structure is of great value. According to the vector angular spectrum representation, the hard edge aperture diffraction by laguerre - axial symmetry polarization Gaussian beam of electromagnetic field is decomposed into TE and TM term two parts, and using the method of stationary phase axial symmetry polarization laguerre - is deduced Gaussian beams through the circular Kong Guang aperture diffraction of TE and TM of the analytic expression of electromagnetic field in the far field. The radial polarization beam, angular polarization beam and free space can be as a special case of our theoretical model. Analysis shows that does not change the existence of axisymmetric circular Kong Guang column vector structure and polarization properties of polarized beam. Waist width and the ratio of wavelength and beam order number and truncation parameter and the electric field vector and the Angle between the radial of the four parameters to the axisymmetric polarization beam through a circular Kong Guang aperture diffraction in the far field after TE item can flow distribution, flow distribution, TM can always flow distribution. The vector characteristics of the beam in optical detection, microscopy, optical storage, optical communication and laser processing effect has been widely in the field of research. However, most of this work is limited to the space uniformly polarized beam, such as linear polarization, circular polarization, and elliptic polarization. Gori in 2001 based on the Jones vector is proposed for a class of non-uniform polarization beam, axial symmetry polarization beam is one of the special structure of non-uniform polarization, polarization Angle to the radial polarization and polarization is axisymmetric two typical polarization. Radial polarization beam with axial symmetry structure and hollow ring intensity distribution of the electric field vector, it can produce after high numerical aperture lens focused intensity bigger longitudinal electric field component, under the same conditions, the radial polarized beam focused spot can reach 0. 16 lambda. 2, for the linear polarization beam, focusing spot is only 0. 16λ2。 Intensity bigger and smaller light spot of longitudinal electric field component accelerates a radial polarization beam in the electronic, optical capture, optical microscope and laser processing, and other fields play an important role. For example, using radial polarization in high power laser beam can be effectively eliminate caused by thermal effect birefringence and the influence of double focus. Under the same conditions for laser cutting, radial polarization beam than the circular polarization beam can achieve higher energy absorption efficiency, namely, cutting speed and cutting depth and increase the product of the factor. 5 - 2 times. Experimental results show that under the same conditions of low carbon steel, laser drilling compared with linear polarization and circular polarization, using angular polarization beam can improve 1. 5 - Four times the processing efficiency.