High-Peak-Power Tunable Source at 550 nm From a Frequency-Doubled Yb-Doped Fiber MOPA

Abstract

A high peak power tunable green source operating in the range of 544-552 nm is here demonstrated through frequency doubling a diode-seeded, nanosecond, polarizationmaintaining, Yb-doped fiber master oscillator power amplifier system. Type-I second harmonic generation was implemented in a lithium triborate crystal via noncritical phase matching by temperature tuning. Narrow-bandwidth green light of average output power of up to 9 W, with a pulse duration of 1.8 ns and peak power of 25 kW, was obtained at a repetition rate of 200 kHz. The pump-to-green conversion efficiency reached 30%. This linearly polarized, narrow bandwidth, tunable source has great potential for applications such as material processing, sensing, and medical research.