Research on Cherenkov-Type Terahertz Radiation Source Based on Lithium Niobate Slab Waveguide

研制了一种基于铌酸锂平板波导结构的切伦科夫辐射型太赫兹辐射源。采用一套由光纤准直镜、平凸聚焦镜和圆柱状棒镜等组成的飞秒激光光束压缩光学系统，成功地将光纤输出的中心波长为1550 nm、重复频率为100 MHz、脉冲宽度为85 fs的飞秒激光脉冲，耦合进入厚度仅有10 μm的掺杂5% MgO:LiNbO3的波导层，获得了6.52 nW的太赫兹波辐射功率。A terahertz (THz) radiation source based on a lithium niobate (LiNbO3) slab waveguide structure utilizing Cherenkov radiation has been developed. By employing a femtosecond laser beam compression optical system composed of a fiber collimator, plano-convex focusing lens, and cylindrical rod lens, the research team successfully coupled femtosecond laser pulses—with a central wavelength of 1550 nm, repetition rate of 100 MHz, and pulse width of 85 fs—output from an optical fiber into a 10-μm-thick waveguide layer of 5% MgO-doped LiNbO3. This achieved a THz radiation power output of 6.52 nW.