The Gaussian impulse fUllction initially assumed in the inverse problem is $e^{-sigma^2chi^2}$. The modified Gaussian amplitude pupil function $e^{frac-{omega^2}{4sigma^2}$ is obtained by the inverse Fourier transform of $e^{-sigma^2chi^2}$. A Gaussian amplitude modulation plate (GAMP) is designed and fabricated by using absorption and transparence glass which are the same refractive index. It is compared the experimental transmittance with theoretical that of GAMP. It is found that the linewidth of Gaussian optical imaging system obtained by wavelength is $0.365{mu}m$ and NA is 0.07 is decrease 2/3 than that of Rayleigh.