Pump-tuned deep-infrared femtosecond optical parametric oscillator across 6-7 μm based on CdSiP2

We report on a high-power femtosecond optical parametric oscillator (OPO) at 80 MHz repetition rate, tunable across 6318–7061 nm in the deep-infrared (deep-IR) using pump wavelength tuning. The OPO, based on CdSiP2CdSiP2 (CSP), is synchronously pumped by a commercial Ti:sapphire-pumped femtosecond OPO in the near-IR, enabling rapid static tuning of the CSP OPO with minimal adjustments to its cavity length. The deep-IR CSP OPO provides as much as 32 mW of average idler power at 6808 nm with spectral bandwidth >1000 nm>1000 nm (at −10 dB−10 dB level) across the tuning range. By implementing intracavity dispersion control, near-transform-limited signal pulses of ∼100 fs∼100 fs duration with smooth single-peak spectrum are achieved at 1264 nm, corresponding to an idler wavelength at 6440 nm. To the best of our knowledge, this is the first time such practical idler powers in the deep-IR have been generated from a dispersion-compensated CSP femtosecond OPO at sub-100 MHz repetition rate.
Peer Reviewed
Postprint (author's final draft)