Chiral interactions are prevalent in nature, driving a variety of biochemical processes. Discerning the two non-superimposable mirror images of a chiral molecule, known as enantiomers, requires interaction with a chiral reagent with known handedness. Circularly polarized light beams are often used as a chiral reagent. Here we demonstrate efficient chiral sensitivity with linearly polarized helical light beams carrying an orbital angular momentum of ±lħ, in which the handedness is defined by the twisted wavefront structure tracing a left- or right-handed corkscrew pattern as it propagates in space. By probing the nonlinear optical response, we show that helicity-dependent nonlinear absorption occurs even in achiral molecules and can be controlled. We model this effect by considering induced multipole moments in light–matter interactions. Design and control of light–matter interactions with helical light may open new opportunities in chiroptical spectroscopy, light-driven molecular machines, optical switching and in situ ultrafast probing of chiral systems and magnetic materials.

手性相互作用在自然界中普遍存在，驱动着各种生化过程。辨别手性分子的两个不可叠加的镜像（称为对映体）需要与具有已知手性的手性试剂相互作用。圆偏振光束通常用作手性试剂。在这里，我们展示了具有 ± lħ轨道角动量的线性偏振螺旋光束的高效手征灵敏度，其中旋性由扭曲的波前结构定义，当它在空间中传播时跟踪左手或右手开瓶器模式。通过探测非线性光学响应，我们表明即使在非手性分子中也会发生依赖于螺旋度的非线性吸收并且可以控制。我们通过考虑光-物质相互作用中诱发的多极矩来模拟这种效应。使用螺旋光设计和控制光与物质的相互作用可能会在手性光谱学、光驱动分子机器、光学开关以及手性系统和磁性材料的原位超快探测方面开辟新的机会。