Separation of photonic crystal modes using femtosecond time-of-flight in waveguides

Summary form only given. The structuring of planar waveguides with 2D photonic crystals is promising for a whole new range of dense optoelectronics; integrated components. In particular coherent multiple scattering can be utilised for the extreme manipulation of both spectral and temporal dispersion. However very little work yet exists showing how light in reality propagates through such structures.. Many issues such as scattering loss, mode mixing, polarisation mixing and structure optimisation remain unresolved. These can only be addressed through the development of suitable tools which separate the different processes in the distinct spectral regions. We use ultrabroadband ultrashort-pulse time-of-flight measurements to resolve how light propagates through photonic crystal and quasicrystal waveguides.