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arXiv · 1511.02973

Cavity-Enhanced Ultrafast Transient Absorption Spectroscopy

Melanie A. R. Reber·Yuning Chen·Thomas K. Allison
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Abstract

We present a new technique using a frequency comb laser and optical cavities for performing ultrafast transient absorption spectroscopy with improved sensitivity. Resonantly enhancing the probe pulses, we demonstrate a sensitivity of $Δ$OD $ = 1 \times 10^{-9}/\sqrt{\mbox{Hz}}$ for averaging times as long as 30 s per delay point ($Δ$OD$_{min} = 2 \times 10^{-10}$). Resonantly enhancing the pump pulses allows us to produce a high excitation fraction at high repetition-rate, so that signals can be recorded from samples with optical densities as low as OD $\approx 10^{-8}$, or column densities $< 10^{10}$ molecules/cm$^2$. This high sensitivity enables new directions for ultrafast spectroscopy.

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Melanie A. R. Reber, Yuning Chen, Thomas K. Allison. 2015-11-10. Cavity-Enhanced Ultrafast Transient Absorption Spectroscopy. https://doi.org/10.1364/optica.3.000311

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