By combining erbium-doped fiber sources based on a large mode-area design and periodically poled lithium niobate, we have obtained single-pass conversion efficiencies of as much as 83% (energy efficiency) for second-harmonic generation into the near IR (768 nm) and of 34% for sum-frequency generation into the green (512 nm) for nanosecond pulses, using first-order quasi-phase matching. Pulse energies in excess of 80µJ of second harmonic have been obtained from systems pumped by a single laser diode.
© 1998 Optical Society of America
D. Taverner, P. Britton, P. G. R. Smith, D. J. Richardson, G. W. Ross, and D. C. Hanna, "Highly efficient second-harmonic and sum-frequency generation of nanosecond pulses in a cascaded erbium-doped fiber:periodically poled lithium niobate source," Opt. Lett. 23, 162-164 (1998)