Continuous-wave injection-seeded multipass OPA for direct 1 W, 76 MHz, sub-50 fs pulse generation at 1.5-1.7 µm

Generating sub-50 fs laser pulses in the near-IR using nonlinear down-conversion is challenging due to the fundamental tradeoff between amplification bandwidth and gain. Conventionally, such ultrashort pulses in the near-IR are generated by optical parametric oscillators (OPOs)/optical parametric amplification (OPA) or OPO/OPA combinations, but the aforementioned challenges and the additional complexity remain, often requiring even several OPA stages. An elegant solution to circumvent this added complexity of an additional OPO is a continuous-wave (cw)-seeded OPA. However, such a setup usually encompasses a complex combination of multiple OPA stages. To avoid these problems, we here utilize our recently introduced compact multipass OPA technology to demonstrate a cw-seeded, extremely compact and simple, low-noise sub-50 fs watt-scale OPA that is tunable in the near-IR from 1.5 to 1.7 µm.