双光子辐照下的螺吡喃聚合物薄膜偏振全息光栅记录研究  

Polarization Holographic Grating Recording in Spiropyran Doped Polymers Under Bi-photonic Irradiations

作　　者：郑美玲[1] 谢鑫[1] 苏玲俐[1] 李本天 付申成[1] 石峰 王秀莉[3] 

机构地区：[1]长春理工大学理学院,长春130022 [2]微光夜视技术重点实验室,西安710065 [3]东北师范大学生命科学学院,长春130024

出　　处：《光子学报》2015年第2期28-32,共5页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.61007006;31271442)资助

摘　　要：螺吡喃聚合物薄膜在短波辐照后的曝光灵敏度和偏振敏感性均得到显著提升.基于这一特性,在线偏振的蓝紫光(405nm)伴随下,用两束耦合的绿光(532nm)以s-p的记录模式在螺吡喃掺杂的PMMA聚合物薄膜上构建全息光栅,并通过低功率红光(632.8nm)进行探测.在405nm和532nm双光子共同作用下,衍射效率动力学特性强烈依赖于辅助光功率.研究发现,405nm激光辐照产生了两种作用:一方面为记录光提供了可取向的部花青分子;另一方面,扰乱了532nm激光形成的折射率光栅并降低了部花青分子的转化活性.考虑到光栅随机光场区的部花青分子聚集体的存在,本文建立了包含衍射效率与各分子光响应速率关系的理论模型.实验数据与拟合结果精准吻合,有效地解释了偏振全息记录中螺吡喃与部花青分子相互转化的微观机制.The exposure sensitivity and polarization sensitivity of spiropyran doped polymers after the irradiation in short-wavelength range were significantly improved.Based on such properties,holographic grating recordings accompanying with a linearly polarized blue-violet beam（405nm）in the photochromic film were performed by two coherent green beams（532nm）for s-p formation.Under the bi-photonic action of 405 nm and 532 nm,temporal evolution of diffraction efficiency was strongly dependent on auxiliary light intensity.It was found the blue-violet irradiation plays double roles in holographic recordings：on one hand,providing the molecular orientationable merocyanine for the recording beams;on the other,disrupting the formation of refractive index gratings and reducing the conversion activity of merocyanine molecule.Taking the existence of merocyanine aggregation in the random light field of interference fringes into account,an theoretical model was established which reveals the relationship between diffraction efficiency and light-rate-constant of each molecular.The experimental results are precisely fitted with this model,the microscopic reaction mechanism of spiropyran and merocyanine molecules in polarization holographic recording was effectively explained.

关 键 词：全息光栅 偏振 动力学 螺吡喃 部花青 光化学反应 光致变色 

分 类 号：O438.1[机械工程—光学工程]