Carrier-wave self-steepening and applications to high-order harmonic generation S. B. P. Radnor, L. E. Chipperfield, P. Kinsler, G. H. C. New Department of Physics, Imperial College, Prince Consort Road, London SW7 2AZ, United Kingdom. Phys. Rev. A77, 033806 (2008). also arXiv.org:0803.3597 We show that carrier-wave steepening and shocking is not restricted to materials with a third-order nonlinearity. We extend predictions for shocking distance to allow for an arbitrary perturbative nonlinearity, and present a range of steepened waveforms on the point of shocking. For high harmonic generation, we demonstrate that gradient-maximized self-steepened pulses like those generated by a second-order nonlinearity can raise the spectral cut-off and yield shorter attosecond pulses. We present simulations of the high-harmonic generation process to demonstrate the possible enhancement. Additional Keywords: sub-cycle, multi-color HHG, carrier-wave sculpting, carrier-wave shaping Email: Dr.Paul.Kinsler@physics.org