Milliwatt-Level Multi-Octave Mid-Infrared Generation by a Diode-Pumped Cr:ZnS Oscillator

The technique of intra-pulse difference frequency generation (IDFG) is highly sought after for delivering broadband mid-infrared (MIR) radiation (2.5-20 µm) in a robust single-beam geometry [1] . Featuring intrinsic carrier-envelope phase stabilization, the few-cycle output pulses can be directly used for numerous emerging time-domain and frequency comb applications [2] , [3] . However, a complex chain of amplification, pulse compression and parametric conversion stages is typically required to drive IDFG in an efficient manner. Here, we report a novel and powerful directly diode-pumped Cr:ZnS oscillator to generate a multi-octave-spanning MIR spectrum.