In this study, both the intersubband optical absorption coefficients and the refractive index changes in triple quantum well (TQW) with different well shapes for different barrier widths is theoretically calculated within framework of the effective mass approximation. Results obtained show that intersubband transitions and the energy levels in triple quantum well can importantly be modified and controlled by the barrier width. By considering the variation of the energy differences, it should point out that by increasing barrier width we can obtain a blue or red shift in the intersubband optical transitions. The sensitivity to the barrier width of the absorption coefficient and the refractive index changes can be used in various optical semiconductor device applications.