In-line synthesis of multi-octave phase-stable infrared light.

Parametric downconversion driven by modern, high-power sources of 10-fs-scale near-infrared pulses, in particular intrapulse difference-frequency generation (IPDFG), affords combinations of properties desirable for molecular vibrational spectroscopy in the mid-infrared range: broad spectral coverage, high brilliance, and spatial and temporal coherence. Yet, unifying these in a robust and compact radiation source has remained a key challenge. Here, we address this need by employing IPDFG in a multi-crystal in-line geometry, driven by the 100-W-level, 10.

Broadband dispersive Ge/YbF mirrors for mid-infrared spectral range.

Broadband dispersive mirrors operating in the mid-infrared spectral range of 6.5-11.5 μm are developed for the first time, to the best of our knowledge.

Mid-infrared long-pass filter for high-power applications based on grating diffraction.

A gold-coated silicon grating has been developed, enabling efficient spatial separation of broadband mid-infrared (MIR) beams with wavelengths >5  μm from collinearly propagating, broadband, high-power light in the near-infrared (NIR) spectral range (centered at 2 μm). The optic provides spectral filtering at high powers in a thermally robust and chromatic-dispersion-free manner such as that necessary for coherent MIR radiation sources based on parametric frequency downconversion of femtosecond NIR lasers. The suppression of a >20  W average-power, 2 μm driving pulse train by three orders of magnitude, while retaining high reflectivity of the broadband MIR beam, is presented.