Non-reciprocal ultrafast laser writing
Non-reciprocal ultrafast laser writing
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DOI：
10.1038/nphoton.2007.276
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发表时间：
2008-02-01
期刊：
影响因子：
35
通讯作者：
Svirko, Yuri P.
中科院分区：
文献类型：
--
作者：
Yang, Weijia;Kazansky, Peter G.;Svirko, Yuri P.
光敏性是一种与许多现象和应用相关的材料特性，从光合作用和摄影到光学数据存储和超快激光写入。人们普遍认为，在均匀介质中，光敏性和相应的光诱导材料修饰不会随着光传播方向的反转而改变。在这里，我们证明，当飞秒激光束的方向从 +z 方向反转到 -z 方向时，沿 +y 和 -y 方向平移光束时写入 LiNbO3 晶体中的结构会被镜像。因此，在非中心对称介质中，对于沿相反方向传播的光，材料的改性可能会有所不同。这是非互易光敏性新光学现象的第一个证据。我们用光压和相关热流来解释这种效应，导致均匀介质中的温度梯度，在均匀强照射下没有反演对称性。
Photosensitivity is a material property that is relevant to many phenomena and applications, from photosynthesis and photography to optical data storage and ultrafast laser writing. It was commonly thought that, in a homogeneous medium, photosensitivity and the corresponding light-induced material modifications do not change on reversing the direction of light propagation. Here we demonstrate that when the direction of the femtosecond laser beam is reversed from the +z to -z direction, the structures written in LiNbO3 crystal when translating the beam along the +y and -y directions are mirrored. In a non-centrosymmetric medium, modification of the material can therefore differ for light propagating in opposite directions. This is the first evidence of a new optical phenomenon of non-reciprocal photosensitivity. We interpret this effect in terms of light pressure and associated heat flow, resulting in a temperature gradient in homogeneous media without inversion symmetry under uniform intense irradiation.