Path to a 100 kHz 2D IR spectrometer based on a tunable Er fiber front end

2D mid-IR spectroscopy is a powerful tool for revealing structure and dynamics in chemical systems. Recently systems operating at 100 kHz have been shown to have improved signal to noise as compared to 1 kHz Ti:Sa systems, as well as faster collection rates allowing more challenging experiments such as 2D IR microscopy. We present a tunable, 100 kHz mid-IR source for 2D IR spectroscopy based on an Er fiber front end which allows for the generation of both pump and signal beams for a three-stage magnesium doped periodically poled lithium niobate (PPLN) optical parametric chirped pulse amplifier (OPCPA). The use of a Raman shift in a photonic crystal fiber (PCF) allows for the PPLN seed to be easily tuned from 1660 nm to 1760nm. Difference frequency generation (DFG) of the PPLN outputs in a zinc germanium phosphate (ZGP) crystal generates mid-IR outputs tunable from 4 µm to 6.5 µm and supporting pulse durations of 42-65 fs, respectively.