Optical pulse compression: bulk media versus hollow waveguides

Optical pulse-compression systems based on bulk materials and hollow wavegu ides are compared by use of coupled-mode theory. Our analysis reveals an in tuitive picture of the temporal and spatial nonlinear processes involved in pulse compression. Further, simple formulas are derived that give an estim ate of the spatial distortions and of the self-phase modulation induced by Kerr nonlinearity. Finally, a parameter regime is identified in which self- focusing in bulk media is suppressed, resulting in a substantial improvemen t in the spatial beam quality of the compressed pulses. (C) 2000 Optical So ciety of America.