Tripathi Saroj R, Taira Yuusuke, Hayashi Shin'ichiro, Nawata Kouji, Murate Kousuke, Minamide Hiroaki, Kawase Kodo
Opt Lett. 2014 Mar 15;39(6):1649-52. doi: 10.1364/OL.39.001649.
The importance of terahertz (THz) wave techniques has been demonstrated in various fields, and the range of applications is now expanding rapidly. However, the practical implementation of THz science to solve the real-world problems is restricted due to the lack not only of convenient high power THz wave emitters and sensitive detectors but also of efficient quasi-optical active devices such as amplifiers. In this work, we demonstrate the direct amplification of THz waves in room temperature using magnesium oxide-doped lithium niobate (MgO:LiNbO3) crystals as the nonlinear gain medium. The input THz wave is injected as a seed beam along with the pump beam into the nonlinear crystal and it is amplified by the optical parametric process. We report gain in excess of 30 dB with an input THz pulse energy of less than 1 pJ. We believe that this demonstration will contribute to the convenience and further applicability of THz frequency techniques.
太赫兹（THz）波技术的重要性已在各个领域得到证明，并且其应用范围目前正在迅速扩大。然而，由于不仅缺乏便捷的高功率太赫兹波发射器和灵敏的探测器，还缺乏诸如放大器等高效的准光有源器件，太赫兹科学在解决实际问题中的实际应用受到限制。在这项工作中，我们展示了使用掺氧化镁铌酸锂（MgO:LiNbO3）晶体作为非线性增益介质在室温下直接放大太赫兹波。输入的太赫兹波作为种子光束与泵浦光束一起注入到非线性晶体中，并通过光参量过程进行放大。我们报告了在输入太赫兹脉冲能量小于1 pJ的情况下增益超过30 dB。我们相信这一演示将有助于太赫兹频率技术的便利性和进一步的适用性。
