1. B. Kippelen, E. Hendrickx, J. L. Maldonado, G. Guillemet, B. L. Volodin, D. D. Steele, Y. Enami, Sandalphon, Y. J. Yao, J. F. Wang, N. Peyghambarian, Optical Sciences Center, University of Arizona, Tucson, AZ 85721, USA.
2. S. R. Marder, Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA, and Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
3. H. Röckel and L. Erskine, Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA.