非线性光学格子中的光束演化研究

Investigation of the beam evolution in nonlinear optical lattice

研究光学格子中(即在光传输的横截面上存在周期格子势的调制)光束的演化,利用变分原理,求出了光束宽度、振幅、频率啁啾参量随传播距离的演化形式.发现光束宽度与调制周期的比值必须小于一定的值才能形成孤子的传输;同时,还得到了光束在不同的条件下存在着不同的传输过程.光学格子中周期格子的作用有类似非线性的良好的特性,周期格子的引入提供了可以更好地控制格子孤子的形成和传输的参考条件.

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.