(Received April 29, 1998; revised August 11, 1998 )
A MachZehnder interferometer was developed for accurately measuring relative phase shifts of light propagating in photonic colloidal crystals deep into the stop bands. These phase shifts can be used to determine the change in index of refraction and the optical dispersion relation from photonic band structure near the band edges. Phase measurements of colloidal crystals incorporating an impurity peak in the transmission spectrum are also presented. © 1998 Optical Society of America
PII: S0740-3224(98)01211-9
PACS: 42.70.Qs, 78.20.Ci, 42.70.Jk, 07.60.Ly, 42.50.-p, 63.50.+x, 71.55.Jv, 82.70.Dd