NOPA

In the kHz lab we operate a two-stage noncollinear optical parametric amplifier (NOPA) which was built at the Chair Leitenstorfer. The input signal is the 780 nm Ti:sapphire pulse. First, self-phase modulation in sapphire is used to generate a white light continuum in the wavelength range between 500 nm and 700 nm. In parallel, the second harmonic of the Ti:sapphire pulse is generated. Subsequently, the white light is amplified up to 12 µJ in two BBO crystals using the optical parametric process with the generated second harmonics as pump radiation. Due to the noncollinear design of the setup, the pump radiation can be easily filtered out. The broad spectrum of the white light enables compression of the generated radiation to ultra-short pulse durations of less than 6 fs using chirped mirrors (CM) and fused silica wedges (FSW).