High Gain Frequency Domain Optical Parametric Amplification

The powerful technique of optical parametric amplification (OPA) experienced a huge advance with the invention of optical parametric chirped pulse amplification (OPCPA) and later noncollinear OPA. In this paper, we describe a radically different approach of performing parametric interaction in the frequency domain instead of the time domain. The frequency domain is reached via optical Fourier transformation, which provides a separation ansatz. It allows breaking down a big task into smaller ones which ultimately enables simultaneous up-scaling of peak power and bandwidth. The first proof-of-concept experiment yielding 1.4 mJ, two cycle pulses at 1.8-μm wavelength is complemented by a high gain (>2000) setup at 800-nm wavelength with 2.5 kHz repetition rate. A very low amount of parasitic superfluorescence without degradation of the picosecond pulse contrast within the pump pulse duration has been observed upon high gain conditions.