Nondiffracting Images under Coherent Illumination

s and utilizing a detector's intensity response to yield arbitrary PND binary images. We begin by considering the image constraints imposed by the detector. A typical detector response curve 11 is shown in Fig. 1. Below some threshold intensity I 0 the incident illumination is not detected; above some intensity I 1 the illumination is detected; and between these two levels the detector behaves unpredictably. It is this intermediate region that we with to avoid. This allowed intensity variation affords us a degree of freedom in designing the mask---instead of imposing a transmissivity of zero or one (binary transmission) , we are allowed in dark regions to transmit an amplitude as high as p I 0 and in light regions as low as p I 1 . Additionally, since the detector is insensitive to the f ield's phase, we may implement an arbitrary phase shift at each mask pixel and therefore design the phase distribution to maximize our image's focal depth. We are now in a position to tackle th