Yang Huimei, Qi Jiwei, Pan Chongpei, Lu Yao, Wu Qiang, Yao Jianghong, Xu Jingjun
Opt Express. 2017 Jun 26;25(13):14766-14773. doi: 10.1364/OE.25.014766.
A kind of lateral excitation (LE) configuration is proposed for quasi-monochromatic terahertz generation via impulsive stimulated Raman scattering in a LiNbO (LN) slab waveguide by numerical simulation. In an individual waveguide, maximum efficiency frequency-selective excitation is achieved with linewidth narrower than 38 GHz when phase matching is fulfilled between the pump laser and the generated terahertz (THz) waves. As a result, the frequency and linewidth of narrowband THz waves can be tuned through changing the dispersion of THz waves, which is implemented by adjusting the thickness of host LN slab. Furthermore, Au-Air-LN-Air-Au multilayer LE structure is developed to realize a dramatic change of the dispersion to obtain quasi-monochromatic THz waves, of which the linewidth is achieved as narrow as 10 GHz. In addition, the frequency and linewidth of quasi-monochromatic THz waves are modulated dynamically by varying the distance between LN slab and Au mirrors flexibly. Consequently, the optimized LE structure is expected to boost the development of high-precision and real-time inspection and sensing.
通过数值模拟，提出了一种横向激发（LE）配置，用于在LiNbO（LN）平板波导中通过脉冲受激拉曼散射产生准单色太赫兹波。在单个波导中，当泵浦激光与产生的太赫兹（THz）波之间实现相位匹配时，可实现线宽小于38 GHz的最大效率频率选择性激发。结果，窄带太赫兹波的频率和线宽可通过改变太赫兹波的色散来调谐，这通过调整主体LN平板的厚度来实现。此外，开发了Au-Air-LN-Air-Au多层LE结构以实现色散的显著变化，从而获得线宽窄至10 GHz的准单色太赫兹波。此外，通过灵活改变LN平板与金镜之间的距离，可动态调制准单色太赫兹波的频率和线宽。因此，优化的LE结构有望推动高精度实时检测和传感的发展。
