Abstract

Diffractive optical elements as deflectors for optical free-space interconnects have been proposed by several authors.^1,2 Unfortunately, the high flexibility of such elements is in many cases outweighed by the strong chromatic aberrations. Surface relief gratings have commonly a rather low carrier frequency (due to the limited resolution of the lithography) and, therefore, the chromatic aberrations are less severe. For volume gratings with their high carrier frequency a close cascade geometry has been proposed to reduce the chromatic aberrations.^3,4 Another possibility for optical interconnects is spaceinvariant imaging of the transmitters onto the receivers? Both approaches have been demonstrated for an optical backplane (Fig. 1).

© 1994 IEEE