N. Scherer, J. E. Jureller, T. A. Birks, W. J. Wadsworth, and P. S. J. Russell, "Widely tunable femtosecond pulses from a tapered fiber for ultrafast microscopy and multiphoton applications," in The Thirteenth International Conference on Ultrafast Phenomena, 2002 OSA Technical Digest Series (Optical Society of America, 2002), paper TuE40.