Chiroptical and optical activity effects involve differential interactions between matter and light. Generally this involves chiral molecules absorbing or scattering right- and left-handed circularly polarized photons at different rates due to the chiroptical interplay of molecular and optical chirality. Laser light which propagates with a helical phase and twisted wavefront possesses optical orbital angular momentum. These optical vortices can twist either clockwise or anticlockwise, and as such they exhibit an optical handedness or chirality completely distinct from that of circular polarization. It has recently been established that the linear optical effects of single-photon absorption and scattering can exhibit optical activity and chiroptical interactions with respect to the optical vortex handedness. Here a fundamental mechanism of optical activity for twisted light is exhibited in nonlinear processes, with specific emphasis on hyper-Rayleigh and hyper-Raman scattering. In comparison to unstructured or plane-wave light, it is shown that using twisted photons produces novel scattering mechanisms dependent on parameters unique to optical vortex beams. Specifically, the scattered intensity for both hyper-Rayleigh and hyper-Raman optical activity is dependent on the sign and magnitude of the OAM of the incident twisted photons, as well as the transverse position of the chiral scatterer. Moreover, symmetry analysis reveals that, unlike the recently discovered linear optical activity effects with optical vortices, nonlinear scattering of twisted light by chiral molecules leads to a modification of scattering through uniquely weighted individual hyperpolarizability contributions.

中文翻译：

---

使用扭曲光的非线性手性分子光子学：超瑞利和超拉曼光学活动

手性和光学活动效应涉及物质和光之间的不同相互作用。由于分子手性和光学手性的手性相互作用，这通常涉及手性分子以不同的速率吸收或散射右旋和左旋圆偏振光子。以螺旋相位和扭曲波前传播的激光具有光学轨道角动量。这些光学涡旋可以顺时针或逆时针扭曲，因此它们表现出与圆偏振完全不同的光学手性或手性。最近已经确定，单光子吸收和散射的线性光学效应可以表现出相对于光学涡旋旋向性的光学活性和手性相互作用。这里在非线性过程中展示了扭曲光的光学活动的基本机制，特别强调了超瑞利和超拉曼散射。与非结构光或平面波光相比，研究表明，使用扭曲光子会产生新的散射机制，具体取决于光学涡旋光束的独特参数。具体而言，超瑞利和超拉曼光学活动的散射强度取决于入射扭曲光子的 OAM 的符号和幅度，以及手征散射体的横向位置。此外，对称性分析表明，与最近发现的旋光性线性旋光效应不同，