Simple method for mid-infrared frequency comb generation
We have demonstrated a simple new method for the generation of fully stabilized mid-infrared (MIR) frequency combs. The method allows independent and fast control of both the repetition rate and offset frequency. The offset frequency of the generated MIR comb is inherently known; there is no need to measure it. The method is based on continuous-wave seeded fs optical parametric generation (OPG), which takes place in a nonlinear optical crystal. The implementation is remarkably simple (no optical cavities are needed) and produces a comb with high output power and low noise.