In this paper, we utilize the finite-difference time-domain method to analyze the transmission characteristics of the point-defected periodical dielectric waveguides (point-defected PDWGs). Each point-defected PDWG contains a defected cylinder distinct from the others. It is found that the optical transmittance becomes worse due to the shorter defected cylinder but it is not affected by the longer one. Moreover, the optical transmission is very sensitive to the radius of the defected cylinder whatever it is larger or smaller than that of the other cylinders.
