DIFFRACTION EFFICIENCY OF RANDOM BINARY-AMPLITUDE DIFFRACTING SCREENS

The diffraction characteristics of random binary-amplitude diffracting screens are investigated. It is shown that, for such a random diffrac ting screen with complex amplitude transmittance t equal to either 0 o r 1, the diffraction efficiency of the screen is maximized when 50% of the screen has transmittance t = 1, independent of other characterist ics of the screen. The maximum diffraction efficiency equals 1/4. For this result to hold the screen must be adequately modeled by a station ary binary random process.