In this article, lasing characteristics of a newly designed ytterbium-doped modified hybrid multi trench fiber (YDMHMTF) has been numerically investigated for strongly pumped conditions. The designed YDMHMTF is maintained single-mode condition with an effective mode area of 1300$\mu m^2$ at the wavelength of 1064 nm for the compact bending radius of 7.5 cm. The radius of doped region is varied up to a maximum core size of ~19 µm through numerical simulations to achieve maximum conversion efficiency for the straight and bending cases. The effective signal overlap factor is ensured by introducing a high-index arc in the inner trench of fiber along with a maximum doped core region. A 1.5 m length of highly bend LMA YDMHMTF shows slope efficiency of 74% and conversion efficiency of 75% when pumped with a laser source of 975 nm. Further, the high slope efficiency of 81% and conversion efficiency of 80% are achieved with aid of a 2 m length YDMHMTF for the straight and practical bending conditions. Therefore, the proposed YDMHMTF can be utilized to develop an efficient compact laser system suitable for industrial lasing applications. Moreover, the fabrication feasibility of our proposed YDMHMTF becomes easier than the photonic crystal fiber and Bragg fiber based designs.

在本文中，已经对强抽运条件下新设计的掺-改性杂化多沟槽光纤（YDMHMTF）的激光特性进行了数值研究。设计的YDMHMTF保持单模状态，有效模式面积为1300$\mu {米}^2$波长为1064 nm时，弯曲半径为7.5 cm。通过数值模拟，掺杂区的半径变化到最大铁芯尺寸为〜19 µm，以实现直线和弯曲情况下的最大转换效率。通过在光纤的内部沟槽中引入高折射率电弧以及最大掺杂纤芯区域，可以确保有效的信号重叠因子。长度为1.5 m的高弯曲LMA YDMHMTF在用975 nm激光源泵浦时显示出74％的斜率效率和75％的转换效率。此外，借助于2m长的YDMHMTF，在直线和实际弯曲条件下，可实现81％的高斜率效率和80％的转换效率。因此，提出的YDMHMTF可以用于开发适用于工业激光应用的高效紧凑型激光系统。