1. A data processor, comprising: a multi-mode threshold laser, having at least 25 independent, traveling wave modes, all of substantially the same frequency; a source of coherent optical radiation of the same frequency as said modes of the multi-mode threshold laser; and a coherent optical computer, for diffracting coherent optical radiation derived from said source and using the diffracted coherent optical radiation to produce twenty-five distinct output beams which are substantially reversals of the beams emitted by said modes of the multi-mode threshold laser; placed adjacent to the multi-mode threshold laser with said output beams impinging on the multi-mode threshold laser; so that each beam of said output beams is injected into exactly one mode of said modes and the oscillation of said mode may be initiated by said output beam.