In an OPO the pump laser beam is split into two distinct beams – Signal and Idler. When the wavelength range of Signal and Idler is not reaching far enough into the mid-Infrared, the two beams can be mixed within the HarmoniXX DFG to significantly extend the wavelength range – even beyond 20 µm.

Within APE’s Difference Frequency Generator, the Signal and Idler are compressed and overlapped in time and space in a non-linear crystal to generate mid-Infrared pulses.

Such wavelengths are required by various applications, such as scattering Scanning Near Field Optical Microscopy (sSNOM), nonlinear spectroscopy in the molecular fingerprint region, FTIR spectroscopy, stand-off detection, identification of volatile compounds, nonlinear physics research, nanophotonics, etc.

The HarmoniXX DFG is specifically designed to interface with APE’s femtosecond and picosecond OPOs. A powerful control software allows the DFG and OPO to self-adjust, automatically tuning Signal and Idler wavelengths as well as the overlap and crystal inside the DFG to generate the desired MIR radiation – minimizing manual interaction. Specially optimized optics drastically reduce pointing, such that the beam position shift is small enough to prevent the need to readjust the subsequent setup.

Latest publication:
https://pubs.acs.org/doi/10.1021/acs.nanolett.3c03479
https://pubs.acs.org/doi/10.1021/acs.jpcc.3c02151

Learn more about HarmoniXX DFG and Levante IR fs:
Mid-IR tunable broadband light source