A technique for multi-band generation is investigated to simultaneously achieve phase-matching in multiple second-order nonlinear processes. By coupling a near-infrared excitation pulse into a LiNbO ₃ planar waveguiding platform, modal phase-matched second harmonic radiation is generated at wavelengths of 403 ± 0.6 nm and Cherenkov-emitted terahertz radiation is generated at frequencies up to ~3.5 THz. For the second harmonic generation process and the terahertz radiation generation process, the conversion efficiencies are measured as $1.5\times 10^{\mathbf {-2}}$ %/(GW-cm ⁻² ) and $1.9\times 10^{\mathbf {-4}}$ %/(GW-cm ⁻² ), respectively. The investigated multi-band generation technique permits a single structure to produce radiation within multiple spectral bands, such that this technique could be used to increase the density of photonic sources on a photonic integrated chip.

中文翻译：

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通过相位匹配的非线性产生过程的多波段光子源

研究了一种用于多频带生成的技术，以在多个二阶非线性过程中同时实现相位匹配。通过将近红外激发脉冲耦合到LiNbO ₃平面波导平台中，在403±0.6 nm的波长处产生模态相位匹配的二次谐波辐射，并在高达〜3.5 THz的频率下产生Cherenkov发射的太赫兹辐射。对于二次谐波产生过程和太赫兹辐射产生过程，转换效率被测量为 $ 1.5 \次10 ^ {\ mathbf {-2}} $ ％/（GW-cm ^-2 ）和 $ 1.9 \乘以10 ^ {\ mathbf {-4}} $ 分别为％/（GW-cm ^-2 ）。研究的多频带产生技术允许单个结构在多个光谱带内产生辐射，因此该技术可用于增加光子集成芯片上的光子源密度。