Helfrich Christof, Frosz Michael H, Tani Francesco
University of Erlangen-Nürnberg, Staudtstraße 7/B2, 91058 Erlangen, Germany.
Max Planck Institute for the Science of Light, Staudtstraße 2, 91058 Erlangen, Germany.
ACS Photonics. 2025 Feb 10;12(2):564-569. doi: 10.1021/acsphotonics.4c02019. eCollection 2025 Feb 19.
We show that twisted single-ring hollow-core fibers can exhibit strong helical dichroism, i.e., a different transmission depending on the orbital angular momentum of the launched light. Experimentally, we observe loss differences of at least 40 dB/m over a broad spectral range (>60 THz). We investigate the effect via analytical and numerical studies and show that considerably higher differential loss can be achieved over a broader spectral range (>180 THz). Our observation provides new routes for controlling the polarization state, extends previous studies of circularly dichroic waveguides, and has many potential applications, such as the realization of new polarizing elements in previously inaccessible spectral regions, chiral sensing, broadband generation of vortex beams, and optical communication.
我们表明，扭曲的单环空心光纤可表现出强烈的螺旋二向色性，即根据所发射光的轨道角动量具有不同的传输特性。在实验中，我们观察到在宽光谱范围（>60太赫兹）内损耗差异至少为40分贝/米。我们通过分析和数值研究来探究这种效应，并表明在更宽的光谱范围（>180太赫兹）内可以实现高得多的差分损耗。我们的观察结果为控制偏振态提供了新途径，扩展了以前对圆二色性波导的研究，并且有许多潜在应用，例如在以前无法进入的光谱区域实现新型偏振元件、手性传感、涡旋光束的宽带产生以及光通信。
