Green and UV frequency conversion of a variable pulse repetition frequency photonic crystal fiber system

摘要

We describe a pulsed green and ultraviolet laser source based on a frequency converted photonic crystal fiber (PCF) amplifier. The flexible-format all-fiber polarization maintaining (PM) seed source consists of cascaded ytterbium doped amplifiers seeded by a directly modulated 1064 nm laser diode. The seed generates pulses fixed at 3.5 ns duration from 20 kHz to 10 MHz. Up to 2.9 W of 532 nm (green) and 1 W of 355 nm (UV) output were obtained in tests from 20-100 kHz using LBO crystals for both the doubling and tripling conversion process. Scaling the pulse energies demonstrated at low repetition rates, to the high repetition rate operation possible with the flexible format seed source, shows the potential for high power, high repetition rate pulsed green and UV output for advanced applications.