title: Femtosecond-laser pumped CdSiP₂ optical parametric oscillator producing 100 MHz pulses centered at 6.2 μm.
abstract: We report the first, to the best of our knowledge, femtosecond-laser-pumped optical parametric oscillator (OPO) based on the newly developed nonlinear crystal, CdSiP₂. The OPO was synchronously pumped by a mode-locked Yb:KYW/Yb:fiber master-oscillator power amplifier, providing 1.053 μm pump pulses with durations of 130 fs at a repetition rate of 100 MHz. The 0.5-mm-thick CdSiP₂ crystal was cut for a type-I noncritical interaction, providing a broad phase-matching bandwidth and ensuring excellent temporal overlap among the pump, signal, and idler pulses. The OPO generated signal pulses with a spectral coverage over 1260-1310 nm and mid-infrared idler pulses with a broad spectral coverage at 5.8-6.6 μm (6.2 THz). With a 2% output coupler (OC), the threshold pump power was 600 mW. At the maximum pump power of 1.6 W, 0.55 W was absorbed due to two-photon absorption and residual linear absorption in the CdSiP₂ crystal, 0.75 W was transmitted, and 53 mW signal power was extracted through the OC. We estimate that the generated idler power was 24 mW.
authors.forename: Zhaowei
authors.initials: Z
authors.lastname: Zhang
authors.forename: Derryck T
authors.initials: DT
authors.lastname: Reid
authors.forename: S
authors.initials: S
authors.lastname: Chaitanya Kumar
authors.forename: Majid
authors.initials: M
authors.lastname: Ebrahim-Zadeh
authors.forename: Peter G
authors.initials: PG
authors.lastname: Schunemann
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Zawilski
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Howle