系统地研究了带有掺氟下陷层的多芯光纤中不同下陷结构参数对串扰特性及模场面积的影响。研究表明，通过调整下陷层的结构参数，在不牺牲低串扰特性的前提下，这种多芯光纤可以实现大的有效面积。另外，详细讨论了下陷层的结构参数对光纤色散及色散斜率的影响，并针对光纤色散问题在实验上得到了验证。分析表明这种低串扰、大有效面积掺氟下陷层多芯光纤在大容量、高功率光纤通信系统中具有重要的潜在应用价值。

The effects of different trench parameters on the crosstalk and the mode area in the trench-assisted multi-core fiber are investigated systematically. Simulations suggest that low crosstalk and/or large mode area can be achieved by adjusting the trench parameters. Furthermore, the effects of different trench parameters on the dispersion characteristic are discussed, and the dispersion characteristics of the structures are verified experimentally. These characteristics suggest that the large-mode-area low-crosstalk trench-assisted multi-core fiber can be an important potential candidate for practical applications.