We theoretically study the effect of the quadratic coupling strength on optomechanical systems subjected to a continuous external force. Quadratic coupling strength originates from strong coupling between the optical and the mechanical degrees of freedom. We show that the quadratic coupling strength reduces the amplitude of the dispersion spectra at the resonance in both blue- and red-sideband regimes. But, it increases (decreases) the amplitude of the absorption spectrum in the blue (red) sideband regime. Besides, in both sideband regimes, the effective detuning between the pump and the cavity deviates with the quadratic coupling strength. Thereby, for an appropriate selection of that quadratic coupling strength, it results in an important magnification (in absolute value) of the group delay for both slow and fast lights exiting from the optomechanical cavity.