The optical parametric chirped-pulse amplification (OPCPA) technique is the key for achieving ultrahigh peak power lasers, whose development is hindered by the rare large aperture mid-infrared nonlinear crystals with high damage thresholds. Here, we present the growth and characterization of a La₃Nb_0.5Ga_5.5O₁₄ (LGN) crystal with a diameter up to 60 mm and high optical quality. Its broadband transparency up to 7.4 μm is attributed to the suppression of the second-order infrared absorption. This work not only provides a promising candidate for the mid-infrared OPCPA system, but also offers a new thought of properly designing nonlinear optical crystals from the perspective of structural properties.

中文翻译：

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用于光学参量啁啾脉冲放大的大口径中红外非线性光学 La3Nb0.5Ga5.5O14 晶体的生长

光学参量啁啾脉冲放大（OPCPA）技术是实现超高峰值功率激光器的关键，其发展受到罕见的大孔径中红外非线性晶体和高损伤阈值的阻碍。在这里，我们展示了直径高达 60 毫米和高光学质量的 La ₃ Nb _0.5 Ga _5.5 O ₁₄ (LGN) 晶体的生长和表征。其高达 7.4 μm 的宽带透明度归因于二阶红外吸收的抑制。这项工作不仅为中红外 OPCPA 系统提供了一个有希望的候选者，而且从结构特性的角度为正确设计非线性光学晶体提供了新思路。