A novel scheme that generates terahertz optical frequency comb (THz OFC) based on optimized cascaded difference frequency generation (OCDFG) with an aperiodically poled lithium niobate (APPLN) crystal is proposed. Two pump lasers initially generate cascaded optical waves by cascaded difference frequency generation (CDFG), the n multiple-frequency THz waves are generated by mixing cascaded optical waves, and finally THz OFC is formed by optimizing phase mismatches of CDFG along the APPLN crystal length. High-performance THz OFC with characteristics of high repetition rate, tunable repetition rate, high flatness and tunable spectral distribution range is exhibited by providing a theoretical calculation. We argue that the scheme based on OCDFG is promising for achieving high-performance THz OFC.

提出了一种基于优化级联差频生成（OCDFG）和非周期极化铌酸锂（APPLN）晶体生成太赫兹光学频率梳（THz OFC）的新方案。两个泵浦激光器首先通过级联差频产生（CDFG）产生级联光波，通过混合级联光波产生n个多频太赫兹波，最后通过优化CDFG沿APPLN晶体长度的相位失配形成太赫兹OFC。通过理论计算，展示了高性能太赫兹无氧光纤具有高重复率、重复率可调、高平坦度和光谱分布范围可调的特点。我们认为基于 OCDFG 的方案有望实现高性能太赫兹 OFC。