Efficient frequency tripling of high-fluence, narrow-band laser pulses is routinely accomplished with a doubling crystal and a sum-frequency mixer. The addition of a second mixer can dramatically improve conversion efficiencies for the large bandwidths of interest for inertial confinement fusion. Designs that involve two doublers similarly offer a higher dynamic range of conversion efficiency versus intensity than the usual two-crystal design.
© 1997 Optical Society of America
D. Eimerl, J. M. Auerbach, C. E. Barker, D. Milam, and P. W. Milonni, "Multicrystal designs for efficient third-harmonic generation," Opt. Lett. 22, 1208-1210 (1997)