Duringthethreeyearssincethefirsteditionofthisbookwaspublished,thestudyofphotoniccrystalshasmadesteadyprogress.Thepropagationofelectromagneticwavesinvarioustypesofphotoniccrystalhasbeeninvestigatedthoroughlybymanyresearcherssothatthebasisforpracticalapplicationsisnowfirmlyestablished.