  Frequency comb and field-resolved broadband absorption spectroscopy are
promising techniques for rapid, precise, and sensitive detection of short-lived
atmospheric pollutants on-site. Enhancing detection sensitivity in absorption
spectroscopy hinges on bright sources that cover molecular resonances and fast
signal modulation techniques to implement lock-in detection schemes
efficiently. Yb:YAG thin-disk lasers, combined with optical parametric
oscillators (OPO), present a compelling solution to fulfill these requirements.
In this work, we report on a bright OPO pumped by a Yb:YAG thin-disk Kerr-lens
mode-locked oscillator delivering 2.8 W, 114 fs pulses at 2.06 {\mu}m with an
averaged energy of 90 nJ. The OPO cavity operates at 30.9 MHz pulse repetition
rates, the second harmonic of the pump cavity, allowing for broadband,
efficient, and dispersion-free modulation of the OPO output pulses at 15.45 MHz
rate. With 13% optical-to-optical conversion efficiency and a high-frequency
intra-cavity modulation, this scalable scheme holds promise to advance the
detection sensitivity and frontiers of field-resolved spectroscopic techniques.
