The phase of modes in three-core optical fibers under high thermal load is studied by means of the combined thermal and optical models. In particular, the effects of thermal dissipation in the doped cores, as a result of quantum defect heat generation, and the relative material refractive index variation are investigated. The induced index gradient can influence the guided mode propagation in multiple adjacent cores, even if their distance is enough to decouple them optically, showing a remarkable dephasing of the different fiber output beams. This effect brought by the thermal phenomenon inherent in the amplification process has to be carefully accounted for when designing multi-core high-power optical lasing and amplifying devices. The mode dephasing results also provide useful information for future evaluation of thermo-optic coupling effects that may occur along the fiber under high power regime.

中文翻译：

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三芯光纤的模式相位变化和热负荷敏感性


利用热光联合模型研究了高热负荷下三芯光纤的模式相位。特别是，研究了由于量子缺陷热量产生而导致的掺杂核热耗散的影响以及相对材料折射率的变化。诱导的折射率梯度会影响多个相邻纤芯中的导模传播，即使它们的距离足以将它们光学解耦，从而显示出不同光纤输出光束的显着相移。在设计多核高功率光学激光和放大器件时，必须仔细考虑放大过程中固有的热现象带来的影响。模式相移结果还为未来评估高功率状态下沿光纤可能发生的热光耦合效应提供了有用的信息。