基于氟化镁晶体微腔产生宽光谱范围克尔光频梳及色散调控研究

Research on generating broad-spectrum Kerr optical frequency comb and dispersion control based on magnesium fluoride crystal micro-resonator

为了在基于回音壁模式光学微腔的光学频率梳生成中优化微腔的性能和光频梳的质量,对氟化镁晶体微腔的色散调控进行研究。首先,理论仿真研究了MgF_(2)晶体微腔边缘形状对腔内模场和总色散的影响;接着根据仿真结果实际加工了两种面形的MgF_(2)晶体微腔,分别为边缘平面型和单边楔形;然后,搭建了微腔性能检测系统和晶体微腔光梳生成系统,实测加工出的MgF_(2)晶体微腔样品的品质因子(Q值)最高可达1.1×10^(8);最后在加工的两种面形晶体腔中均有效激发了超过200 nm的宽光谱范围的克尔光频梳。实验结果验证了边缘楔形的微腔结构确实能够有效压缩模场并调控总色散,相比于边缘平面型的微腔能够产生更宽光谱范围的光梳。

The controlled dispersion of a magnesium fluoride crystal resonator was studied to optimize the performance of the whispering gallery mode(WGM)resonator and the quality of generated optical frequency combs(OFCs)based on the WGM optical resonator.Firstly,the effect of the edge shape of a MgF_(2) crystal resonator on the cavity mode field and total dispersion was investigated by theoretical simulation.Thereafter,two kinds of MgF_(2) crystal resonators were fabricated according to the simulation results,namely plane edge and unilateral wedge types,respectively.The resonator performance detection and crystal resonator optical frequency comb generation systems were established,and the quality factor(Q factor)of the processed MgF_(2)crystal resonator samples was recorded up to 1.1×10^(8).Finally,the Kerr optical frequency comb,with a wide spectral range of more than 200 nm,was excited in both the planar crystal resonators.The experimental results verified that the edge-wedged micro-resonator structure could effectively compress the mode field and regulate the total dispersion.In addition,a wider spectral range of the OFC could be produced in comparison with the edge-flat micro-resonator.