We show that heavy photon dispersions determining novel applications of photonic crystal waveguides in LEDs and microlasers can be directly accessed by means of surface coupling techniques [1,2].By rigorous scattering matrix treatment of Maxwell equations [3] we analyse the strength of external coupling and the line shape of coupling features in reflectivity spectra as a function of the depth of patterning. By comparison with experiments performed on deeply etched AlGaAs structures we determine detailed heavy photon dispersion curves with the group velocity suppressed at the band edges by two orders of magnitude relative to that in bulk semiconductors. For two dimensional honeycomb lattices of air cylinders we show that photonic dispersions with pronounced heavy photon properties at k-vectors within the first Brillouin zone can be achieved due to anticrossing and polarisation mixing of photonic bands. It is shown that due to the wavevector selective nature of surface coupling, such techniques allow control not only of the group velocity but also of the group velocity dispersion parameter, a key factor in determining the propagation of ultrashort pulses. We demonstrate this control by coupling external light directly to regions with very strong anomalous dispersion opening the prospect for new methods of excitation of gap solitons in photonic crystal waveguides.

[1] V.N.Astratov et al., to appear in 10 July issue of Appl. Phys. Lett. (2000)
[2] V.N.Astratov et al., Phys.Rev.B60, R16255 (1999)
[3] D.M.Whittaker and I.S.Culshaw, Phys.Rev.B60, 2610 (1999)