Automodulations in Kerr-lens Modelocked Solid-State Lasers

Nonstationary pulse regimes associated with self modulation of a Kerr-lens modelocked Ti:sapphire laser have been studied experimentally and theoretically. Such laser regimes occur at an intracavity group delay dispersion that is smaller or larger than what is required for stable modelocking and exhibit modulation in pulse amplitude and spectra at frequencies of several hundred kHz. Stabilization of such modulations, leading to an increase in the pulse peak power by a factor of ten, were accomplished by weakly modulating the pump laser with the self-modulation frequency. The main experimental observations can be explained with a round trip model of the fs laser taking into account gain saturation, Kerr lensing, and second- and third-order dispersion.Comment: 21 pages, 9 Postscript figures, TeX, the calculations are presented on http://www.geocities.com/optomaple

Nonlinear interaction between two different photonic bandgaps of a hybrid photonic crystal fiber

Nonlinear interaction between spectral components in two different photonic bandgaps is experimentally demonstrated by launching femtosecond pulses near a zero-dispersion wavelength of a hybrid photonic crystal fiber, which guides by a combination of total internal reflection and bandgap effects. It is demonstrated that the initial pulse becomes spectrally broadened, and narrowband resonant radiation is generated in a different bandgap from the one responsible for guiding at the pump wavelength. The spectral intensity of the resonant radiation peaks at 2.7 dB below that of the broadened pulse in the pump-guiding bandgap. © 2008 Optical Society of America.331820802082A. Cerqueira S. Jr., F. Luan, C. M. B. Cordeiro, A. K. George, and J. C. Knight, Opt. Express 14, 926 (2006)Litchinitser, N.M., Dunn, S.C., Steinvurzel, P.E., Eggleton, B.J., White, T.P., McPhedran, R.C., Sterke, C.M., (2004) Opt. Express, 12, p. 1540Jasapara, J., Her, T.H., Bise, R., Windeler, R., Digiovanni, D.J., (2003) J. Opt. Soc. Am. B, 20, p. 1611Biancalana, F., Skryabin, D.V., Yulin, A.V., (2004) Phys. Rev. E, 70, p. 016615Akhmediev, N., Karlsson, M., (1995) Phys. Rev. A, 51, p. 2602Fuerbach, A., Steinvurzel, P., Bolger, J., Eggleton, B., (2005) Opt. Express, 13, p. 2977Schreiber, T., Röser, F., Schmidt, O., Limpert, J., Iliew, R., Lederer, F., Petersson, A., Tünnermann, A., (2005) Opt. Express, 13, p. 762