In this paper, transmission spectrum and output intensity
profile of a 1D photonic crystal micro-cavity is studied by using the
transfer matrix method. It is shown that the transmission spectrum
characteristics of the structure irradiated by a Gaussian beam are
noticeably different from the plane-wave irradiation transmission
spectrum. A ring-shape output intensity profile is observed under
irradiation of a common Gaussian beam profile. The various
characteristics of output intensity profile are investigated.