Optical transition with changes of frequency and wave vector can be induced by optically generated free carrier fronts that move along a slow light photonic crystal waveguide and interact with a co-propagating signal wave. With the flexibility in dispersion designs of these waveguides, a variety of indirect photonic transitions can be envisaged. The signal wave transmitted through the front experience an inter-band transition, while the wave reflected from the front - an intra-band transition. Theory and experimental results are presented.
