Kifle Esrom, Mateos Xavier, de Aldana Javier Rodríguez Vázquez, Ródenas Airan, Loiko Pavel, Choi Sun Yung, Rotermund Fabian, Griebner Uwe, Petrov Valentin, Aguiló Magdalena, Díaz Francesc
Opt Lett. 2017 Mar 15;42(6):1169-1172. doi: 10.1364/OL.42.001169.
Depressed-index channel waveguides with a circular and photonic crystal cladding structures are prepared in a bulk monoclinic Tm:KLu(WO) crystal by 3D direct femtosecond laser writing. The channel waveguide structures are characterized and laser operation is achieved using external mirrors. In the continuous-wave mode, the maximum output power of 46 mW is achieved at 1912 nm corresponding to a slope efficiency of 15.2% and a laser threshold of only 21 mW. Passive Q-switching of a waveguide with a circular cladding is realized using single-walled carbon nanotubes. Stable 7 nJ/50 ns pulses are achieved at a repetition rate of 1.48 MHz. This first demonstration of ∼2 μm fs-laser-written waveguide lasers based on monoclinic double tungstates is promising for further lasers of this type doped with Tm and Ho ions.
通过三维直接飞秒激光写入技术，在块状单斜晶系Tm:KLu(WO)晶体中制备了具有圆形和光子晶体包层结构的低折射率通道波导。对通道波导结构进行了表征，并使用外腔镜实现了激光运转。在连续波模式下，在1912 nm处实现了46 mW的最大输出功率，对应斜率效率为15.2%，激光阈值仅为21 mW。利用单壁碳纳米管实现了具有圆形包层的波导的被动调Q。在1.48 MHz的重复频率下获得了稳定的7 nJ/50 ns脉冲。这种基于单斜晶系双钨酸盐的约2μm飞秒激光写入波导激光器的首次演示，对于进一步掺杂Tm和Ho离子的此类激光器具有重要意义。
