High-energy, 3 ps, 1.5 μm optical parametric conversion based on a periodic KTA crystals array

We demonstrate a compact, cavity-free approach to generate high-energy, few-picosecond (<5 ps), high beam quality near and mid-infrared (NIR-MIR) sources. This approach overcomes the size limitation of conventional synchronously pumped optical parametric oscillator (SPOPO). By using a mode self-reproduction periodic array of four KTA crystals pumped by a 1 MHz Nd:YVO₄ MOPA system, we produce microjoule-level pulses from a tens centimeter-scale device. The device delivers 3 ps pulses with 2.6 μJ of energy at 1535 nm (signal light) and 0.8 μJ at 3467 nm (idler light).