Nonlinear effect on optical properties of one-dimensional photonic crystal (1D-PC) of the type (HL) n (LH) m (LLHH) k was investigated. It is an asymmetric hybrid Fabry-Perot resonator type of 1DPC structure which is composed of linear (H layers) and nonlinear (L layers) materials. The linear and nonlinear transmission spectra are graphically illustrated using a numerical approach based on the Transfer Matrix Method (TMM). Results show the appearance of a Perfect Transmission Peak (PTP) in the photonic band gap which makes the structure constitute a monochromatic filter. By analyzing this PTP it is shown that the Full-Width at Half-Maximum (FWHM) depends not only on the number of symmetry layers of the studied 1D-PC but also on the refractive index of the nonlinear layers. The change of the refractive index (Kerr effect) causes a dynamically shift in the band gap including the resonance peak. As a result, such a structure has the potential to be used for designing optical filters and nonlinear optical devices.