用光学线性（偏振紫外－可见吸收）和非线性（旋转样品二次谐波）方法研究了Ｙ型半花菁／花生酸交替ＬＢ多层膜的光致光学各向异性。在纳秒紫外偏振脉冲激光照射下，ＬＢ多层膜中半花菁分子发色团长轴向紫外光偏振方向重新取向。加热可以使ＬＢ多层膜平面内各向异性消失及Ｈ－聚集体分解 Photoinduced optical anisotropy of a Y-type hemicyanine / arachidic alternating LB multilayer films was studied by optical linearity (Polarization UV-Vis absorption) and nonlinearity (Rotating Sample Second Harmonicity). Under the nanosecond UV-pulsed laser irradiation, the polarization direction of the long-axis UV light of the hemicyanine molecule in the LB multilayer film is reoriented. Heating can make the LB multilayer film disappear in the plane anisotropy and H-aggregate decomposition