We present the design of an ultrafast optical parametric chirped pulse amplifier (OPCPA) operating at 3 µm yielding few-cycle pulses and multi-mJ output energy. This design demonstrates that with a configuration of a single crystal or combination of crystals (KTA and MgO:LN) it is possible to achieve output energies above the mJ with sufficient bandwidth to allow compression to just 5-optical cycles. Here, we consider a 1 µm mJ-level picosecond chirped pulse amplifier (CPA), a typical pumping source for this type of non-linear amplifiers. Compression with a simple bulk material enables reaching close to the pulse Fourier-transform limited duration, paving the way to high energy, ultrafast mid-infrared pulses.
Surface-reflection-initiated pulse-contrast degradation in an optical parametric chirped-pulse amplifier