Gorajoobi Shahab Bakhtiari, Murugan Ganapathy Senthil, Zervas Michalis N
Opt Express. 2018 Oct 1;26(20):26339-26354. doi: 10.1364/OE.26.026339.
Coupling strength in taper-coupled microbottle resonators can be tuned by offsetting the taper along the resonator profile, similar to controlling the air-gap in microsphere excitation, and hence, achieve desired coupling characteristics for a specific mode. Such flexibility makes microbottles attractive and adaptable laser cavities. In this paper, lasing characteristics of Yb-doped microbottle laser (MBL) coupled to tapered fiber are theoretically investigated. It is demonstrated that desired lasing characteristics for a particular mode are achievable by controlling the taper-resonator coupling, intrinsic quality factor (Q) and dopant concentration. Although, high Q whispering gallery cavities provide high internal powers, which is favorable especially for low gain materials, they lack high output powers. Hence, care should be taken in designing MBLs to attain the highest possible output power. Here, we address such issues, and optimized the required resonator parameters (for both pump and signal) for a low threshold pump power, high efficiency and desired lasing wavelength.
通过沿谐振器轮廓偏移锥形结构，可以调节锥形耦合微瓶谐振器中的耦合强度，这类似于控制微球激发中的气隙，因此能够针对特定模式实现所需的耦合特性。这种灵活性使得微瓶成为有吸引力且适应性强的激光腔。本文对耦合到锥形光纤的掺镱微瓶激光器（MBL）的激光特性进行了理论研究。结果表明，通过控制锥形 - 谐振器耦合、本征品质因数（Q）和掺杂剂浓度，可以实现特定模式所需的激光特性。尽管高Q回音壁腔提供了高内部功率，这对于低增益材料尤其有利，但它们缺乏高输出功率。因此，在设计微瓶激光器时应注意获得尽可能高的输出功率。在这里，我们解决这些问题，并针对低阈值泵浦功率、高效率和所需激光波长优化所需的谐振器参数（泵浦和信号的参数）。
