lateral spreading is negligible optical cross talk caused by the emitted photon traveling laterally within the wafer can be reduced to a minimum by thinning the substrate 42 to under 50 u03bcm and preferably under about 10 u03bcm or even removing the entire substrate 42 leaving only the epitaxial layers 46 by providing a device wherein this cross talk or smearing is negligible there is no need for pixelizing by providing an array of devices each corresponding to one pixel as in a conventional imaging array in other embodiments of the invention this cross talk or smearing can be eliminated by providing a qwip led 40 that is designed to function in reflection or absorption rather than in transmission with a common input output port face of the device more specifically in a second embodiment of the invention where care is not taken to thin the substrate layer or ensure nearly 100 transmissivity of fir energy through the substrate a reflective layer 45a can be incorporated adjacent the substrate or the qwip led prior to growing the qwip led layers as is shown in fig4 c alternatively a substrate layer 45b having a high reflectivity can be used as illustrated in fig4 d in yet another embodiment of the invention instead of providing a very thin substrate or an effectively reflective layer below the qwip led a substrate or qwip that is highly absorptive can be provided to essentially eliminate smearing of the image produced by providing an absorptive substrate or absorptive layer upon the substrate any light entering this absorptive layer or the absorptive substrate.