title: High-power femtosecond mid-infrared optical parametric oscillator at 7  μm based on CdSiP(2).
abstract: We report a femtosecond optical parametric oscillator (OPO) for the mid-infrared (mid-IR), generating a record average power of 110 mW at 7 μm. The OPO, based on CdSiP(2) (CSP) as the nonlinear crystal, provides idler wavelength tuning across 6540-7186 nm with spectral bandwidths >400  nm at -10  dB level over the entire range, and a maximum bandwidth of 478 nm at 6.9 μm. To the best of our knowledge, this is the highest average power generated from a femtosecond OPO in the deep mid-IR. The OPO also provides near-IR signal wavelengths tunable across 1204-1212 nm with a usable power of 450 mW in 418-fs pulses at 1207 nm. The simultaneously measured signal and idler power exhibit a passive stability better than 1.6% rms and 3% rms, respectively. A mid-IR idler spectral stability with a standard deviation of the frequency fluctuations better than 40 MHz over 15 min, limited by the measurement resolution, is realized. Using the mid-IR idler from the CSP OPO, we perform Fourier-transform spectroscopy to detect liquid phase organic solvent, toluene (C(7)H(8)), in the molecular fingerprint region.
authors.forename: S
authors.initials: S
authors.lastname: Chaitanya Kumar
authors.forename: J
authors.initials: J
authors.lastname: Krauth
authors.forename: A
authors.initials: A
authors.lastname: Steinmann
authors.forename: K T
authors.initials: KT
authors.lastname: Zawilski
authors.forename: P G
authors.initials: PG
authors.lastname: Schunemann
authors.forename: H
authors.initials: H
authors.lastname: Giessen
authors.forename: M
authors.initials: M
authors.lastname: Ebrahim-Zadeh