  Time-resolved near-infrared absorption spectroscopy of single non-repeatable
transient events is performed at high spectral resolution with a dual-comb
interferometer using a continuous-wave laser followed by a single electro-optic
amplitude modulator. By sharing high-speed electrical/optical components, our
spectrometer greatly simplifies the implementation of dual-comb spectroscopy
and it offers a high mutual coherence time, measured up to 50-s, without any
active stabilization system and/or data processing. The time resolution, which
can be reconfigured a posteriori, is as short 100 microseconds in our
experimental demonstration. For a span of 36 GHz, the mean signal-to-noise
ratio of 80, at 100-MHz spectral resolution and 100-microsecond measurement
time, enables the precise determination of the parameters of rovibrational
lines, including intensity or concentration.

Optics;Applied Physics;Atomic Physics;Chemical Physics