Investigation of the beam evolution in nonlinear optical lattice
非线性光学格子中的光束演化研究

The paper studies the beam evolution of optical lattice, i.e. media with transverse periodic lattice modulation in the propagation radiation. Using the variational principle,the forms are obtained for the evolution duing propagation of beam width, beam amplitude and frequency chirp. Next, the conditions for soliton formation in nonlinear optical lattice are discussed and the different propagation processes with different beam conditions are obtained. There are analogous characteristics in the actions of periodic lattice potential of optical lattice and nonlinear media. The periodic potential offers a better method to control the lattice soliton formation and propagation.