This paper reports the effects of insertion loss, laser profile and inhomogeneity of dots distribution on properties of an all-optical modulator based on spherical quantum dot. The aim of this paper is to give a quantitative description for the variation of main properties of an all-optical quantum dot modulator such as, absorption, transmission and modulation depth regard to insertion loss, laser profile and inhomogeneity of dots. To realize these points, first, we extract the field distribution in optical fiber and channel waveguide (modulator) which are defined by their structure characteristics and boundary conditions. Using the electric field equations, input coupling efficiency and insertion loss and also role of laser profile are observable. Finally we investigate the effect of size distribution and inhomogeneity of quantum dots on the modulator performance. In this structure we used electromagnetically induced transparency (EIT) in GaN/AlN structure, associated with inter-sublevel transitions.