当面向高功率径向偏振场激光的产生和传导时,在光纤内实现高的模式区分度与大的模场面积一直是核心的技术挑战。基于此,提出一种全新的径向偏振场光纤设计方案,通过在纤芯内部引入圆对称的径向分布热应力场,使得纤芯内形成径向双折射效应,有效打破常规光纤中偏振模式之间的简并,使TM01模、TE01模和HE21模的有效折射率差为10 -4量级,从而将TM01径向偏振模区分出来。同时,此类径向偏振场光纤更易实现TM01模场的大模面积设计。

High mode discrimination and large mode area in fibers are key technical challenges for the generation and transmission of high-power radially polarized field (RPF) laser. Based on this, a novel method for the design of a radially polarized field fiber is proposed. By introducing a circularly symmetrical radially distributed thermal stress field into the core of the fiber, a radial birefringence effect can be realized in the core, which effectively breaks the degeneracy between polarization modes in conventional optical fibers. The effective index difference among TM₀₁, TE₀₁, and HE₂₁ modes is of the order of 10 ^-4. This allows the TM₀₁ radial polarization mode to be separated. In addition, a large mode area design for the TM₀₁ mode field can be achieved by using the proposed RPF fiber.