An infinite diffraction grating with amplitude transmittance t_A(x,y) = cos(2πxf_o) is illuminated with a unit amplitude normally-incident plane wave. a) What is the field distribution at the immediate RHS of the grating? b) Determine the plane wave spectrum of the fields at the immediate RHS of the grating. c) What is the far-field diffraction pattern of the transmitted fields? d) What is the near-field diffraction pattern? e) Describe how parts a – c would be modified for a grating of finite extent as expressed by the following: t_A(x,y) = rect(x/L_x)rect(y/L_y)cos(2πxf_o).