Phase-matched four-wave mixing in higher-order modes of microstructure fibers allows unprecedentedly high efficiencies of anti-Stokes frequency conversion to be achieved for subnanojoule femtosecond laser pulses. 70-fs pulses of 790-nm radiation were used to generate an anti-Stokes component at 520–530 nm in a higher-order mode of a microstructure fiber with a 4.8 μm core. The maximum ratio of the anti-Stokes signal energy to the energy of the pump component in the output spectrum is estimated as 1.7.
© 2003 Optical Society of America
D. A. Akimov, E. E. Serebryannikov, A. M. Zheltikov, M. Schmitt, R. Maksimenka, W. Kiefer, K. V. Dukel’skii, V. S. Shevandin, and Yu. N. Kondrat’ev, "Efficient anti-Stokes generation through phase-matched four-wave mixing in higher-order modes of a microstructure fiber," Opt. Lett. 28, 1948-1950 (2003)