Large-area periodically-poled lithium niobate wafer stacks optimized for high-energy narrowband terahertz generation.
Large-area periodically-poled lithium niobate wafer stacks optimized for high-energy narrowband terahertz generation.
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DOI：
10.1364/oe.475604
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发表时间：
2022-12
期刊：
影响因子：
3.8
通讯作者：
C. Mosley;D. Lake;D. Graham;S. Jamison;Robert Appleby;G. Burt;M. Hibberd
中科院分区：
文献类型：
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作者：
C. Mosley;D. Lake;D. Graham;S. Jamison;Robert Appleby;G. Burt;M. Hibberd
由定制的大面积晶圆堆叠组成的周期性极化铌酸锂（PPLN）源为系统地研究多周期太赫兹（THz）产生机制提供了独特的机会，因为它们是逐层组装的。在这里，我们研究并优化了 PPLN 晶圆堆叠的太赫兹发射，作为晶圆数量、泵浦能量密度、脉冲持续时间和啁啾、晶圆分离和泵浦聚焦的函数。使用 135 µm 厚、2" 直径的晶圆，我们生成中心频率高达 0.39 THz 的高能窄带太赫兹脉冲，直接适用于太赫兹驱动的粒子加速应用。我们使用电光采样测量探索随着晶圆数量的增加而建立的多周期脉冲，实现高达 0.17% 的太赫兹转换效率，同时展示对这些源提供的脉冲长度和带宽的独特控制。在模拟的指导下，观察到堆叠安装和泵浦聚焦条件的频率依赖性分别归因于晶圆间标准具和古伊相移，揭示了微妙的特征，这些特征对于理解和优化 PPLN 晶圆堆叠源的性能至关重要，以实现最佳窄带太赫兹产生。
Periodically-poled lithium niobate (PPLN) sources consisting of custom-built stacks of large-area wafers provide a unique opportunity to systematically study the multi-cycle terahertz (THz) generation mechanism as they are assembled layer-by-layer. Here we investigate and optimize the THz emission from PPLN wafer stacks as a function of wafer number, pump fluence, pulse duration and chirp, wafer separation, and pump focusing. Using 135 µm-thick, 2"-diameter wafers we generate high-energy, narrowband THz pulses with central frequencies up to 0.39 THz, directly suitable for THz-driven particle acceleration applications. We explore the multi-cycle pulse build-up with increasing wafer numbers using electro-optic sampling measurements, achieving THz conversion efficiencies up to 0.17%, while demonstrating unique control over the pulse length and bandwidth these sources offer. Guided by simulations, observed frequency-dependence on both stack-mounting and pump focusing conditions have been attributed to inter-wafer etalon and Gouy phase-shifts respectively, revealing subtle features that are critical to the understanding and performance of PPLN wafer-stack sources for optimal narrowband THz generation.