Practical Pump-Probe Spectroscopy Considerations for High-Speed and Low-Noise Measurements

Pump-probe spectroscopy is commonly used to study ultrafast phenomena [1]. An ultrashort laser pulse (pump) induces dynamics, which are then measured with another, delayed laser pulse (probe). The probe signal is often weak, making efficient measurements with good signal-to-noise ratio (SNR) challenging. If long integration times are needed to achieve sufficient SNR, applications requiring high speed acquisition, such as 2D pump-probe imaging, become impractical. In this contribution, we optimize three crucial aspects of pump-probe spectroscopy to enable high-speed and low-noise measurements. We show measurements of ultrafast photoacoustics to demonstrate shot-noise-limited performance.