This study investigates the all-optical directional control of emission in a cholesteric liquid crystal (CLC)-infiltrated photonic crystal fiber (PCF) laser. A laser dye-doped CLC (LD-CLC) and an azobenzene LC-doped CLC (ALC-CLC), which are selectively infiltrated into the hollow core and holey-matrix cladding of the PCF, function as an optically active cavity and an all-optical emission direction-controllable light valve, respectively, in the photonic LC fiber (PLCF) laser. Experimental results show that the PLCF has a low energy threshold (approximately 63 nJ/pulse) and a large circular polarization anisotropy (g ≅ 2) in lasing output. The lasing output from the LD-CLC-filled core of the PLCF can be all-optical controlled to emit omni- or semi-directionally or to off-emit by controlling the isothermal phase transition of the CLC between the scattering focal conic state and the transparent isotropic state by the all-optical-induced reversible photoisomerization of the doped ALCs in the cladding region. The emission direction-controllable PLCF laser has significant potential in various applications, such as bio-image, photo-therapy, wearable devices, displays, sensors, and lighting.

中文翻译：

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光子液晶光纤激光器发射的全光定向控制

本研究调查了胆甾型液晶 (CLC) 渗透光子晶体光纤 (PCF) 激光器中发射的全光定向控制。激光染料掺杂的 CLC (LD-CLC) 和偶氮苯 LC 掺杂的 CLC (ALC-CLC) 选择性地渗透到 PCF 的空芯和多孔矩阵包层中，用作光学有源腔和所有-光子LC光纤（PLCF）激光器中的光发射方向可控光阀。实验结果表明，PLCF 在激光输出中具有低能量阈值（约 63 nJ/脉冲）和大圆偏振各向异性 (g ≅ 2)。PLCF 的 LD-CLC 填充核心的激光输出可以通过控制 CLC 在散射焦锥状态和散射焦锥状态之间的等温相变来进行全光控制，以全向或半向发射或停止发射。通过包层区域中掺杂的 ALC 的全光诱导可逆光异构化，形成透明的各向同性状态。发射方向可控的 PLCF 激光器在各种应用中具有巨大的潜力，例如生物图像、光疗、可穿戴设备、显示器、传感器和照明。