利用前向简并四波混频光路,在偶氮苯聚合物薄膜表面制作出六角对称的晶体微结构。观察到多个相位共轭波,当三束入射光都处在p偏振态时,在样品表面可得到一维光栅;当三束入射光中有一束在p偏振态,另两束在s偏振态时,在样品表面上得到的是六角对称微结构。这一结果表明,光场强度周期性变化及光场偏振态对晶格微结构的形成非常重要。

A method for laser induced hexagonal symmetry microstructures in an azobenzene containing polymer film is presented based on forward degenerate four-wave mixing. Multiple forward phase conjugate waves are observed. Three p-polarized input laser beams induce only one-dimensional gratings, but using a proper combination of s-polarized and p-polarized laser beams, hexagonal symmetry microstructures can be induced in the azobenzene polymer film. The experimental results indicate that both the periodic variations of light field intensity and the alternation of the resultant electric field polarization in the film are essential to the formation of the microstructures in the crystal.