Hybrid fs/ps coherent anti-Stokes Raman scattering (CARS) thermometry often utilizes ps probe pulses derived from pulse shaping or spectrally filtering the primary laser source or by synchronization with a low repetition rate external laser. This results in limited energy, spectral resolution, and/or repetition rate of the ps probe. In this work, a master-oscillator power-amplifier (MOPA) laser was synchronized to the oscillator of a Ti:sapphire regenerative amplifier to achieve high-energy (600 µJ), narrowband (58 ps) probe pulses at kHz repetition rates. Temporal filtering allows the pulse characteristics to be adjusted for each application. At 25 Torr, relevant to high-speed flows, the kHz-rate MOPA system generated signal-to-noise ratios 3× higher in nitrogen and had improved precision relative to a 10 ps probe derived from spectral filtering and the power-amplifier. The MOPA system also enabled single-shot ro-vibrational hybrid fs/ps CARS thermometry in 650 K heated air.

中文翻译：

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高能、低抖动、窄带 ps 探针激光器，用于 kHz 速率 fs/ps 相干反斯托克斯拉曼散射

混合 fs/ps 相干反斯托克斯拉曼散射 (CARS) 测温通常利用来自脉冲整形或对主激光源进行光谱过滤或通过与低重复率外部激光器同步而产生的 ps 探测脉冲。这导致 ps 探针的能量、光谱分辨率和/或重复率有限。在这项工作中，主振荡器功率放大器 (MOPA) 激光器与钛蓝宝石再生放大器的振荡器同步，以实现 kHz 重复率的高能 (600 µJ)、窄带 (58 ps) 探测脉冲。时间滤波允许针对每个应用调整脉冲特性。在与高速流动相关的 25 Torr 压力下，kHz 速率 MOPA 系统在氮气中产生的信噪比高出 3 倍，并且相对于源自光谱滤波和功率放大器的 10 ps 探头，精度更高。 MOPA 系统还能够在 650 K 加热空气中进行单次旋转振动混合 fs/ps CARS 测温。