The sensitivity of high-repetition-rate hybrid femtosecond/picosecond (fs/ps) rotational coherent anti-Stokes Raman scattering (RCARS) is strongly influenced by the energy available for the ps probe pulse. In this work, a high-energy ps probe pulse that is time-synchronized with the fs pump/Stokes pulse is achieved by using a diode-pumped Nd:YAG amplifier seeded at 1064.4 nm by the output of a fs optical parametric amplifier. Nearly transform-limited, 10 ps pulses with up to 800 µJ/pulse and a bandwidth of ${1.9}\;{{\rm cm}^{ - 1}}$ were generated at the second harmonic 532.2 nm and used for kilohertz-rate fs/ps RCARS thermometry up to 2400 K with accuracies of 1–2%. We furthermore demonstrate the amplification of variable pulsewidths for flexible single-mode (chirp-free) RCARS signal generation.

中文翻译：

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适用于kHz fs / ps旋转CARS的灵活的无线性调频脉冲探测

高重复率混合飞秒/皮秒（fs / ps）旋转相干反斯托克斯拉曼散射（RCARS）的灵敏度受ps探测脉冲可用能量的强烈影响。在这项工作中，通过使用由fs光学参量放大器的输出注入在1064.4 nm处的二极管泵浦Nd：YAG放大器来实现与fs泵浦/斯托克斯脉冲时间同步的高能ps探测脉冲。在二次谐波532.2 nm处产生接近变换限制的10 ps脉冲，最高800 µJ /脉冲，带宽为{{1.9} \; {{\ rm cm} ^ {-1}} $，用于千赫兹fs / ps速率的RCARS测温仪，精度可达2400 K，精度为1-2％。我们进一步展示了可变脉冲宽度的放大，用于灵活的单模（无线性调频）RCARS信号生成。