Abstract: The light mixing device for the uniform spectral and intensity-related distribution of light coming in from n.times.n optical fibers to n.times.n outgoing optical fibers. The incoming and the outgoing optical fibers are distributed into n groups of n each respectively, each group of optical fibers being optically connected with a first front face of a mixer lamina. The n mixer laminae of the incoming optical fibers are stacked and arranged to form a first stack, and the n mixer laminae of the outgoing optical fibers are stacked and arranged to form a second stack, in each case congruently and above one another in such a manner that the free second front faces of the mixer laminae of both stacks form one surface respectively. The surfaces of both stacks are directed against one another and arranged in a manner in which they are rotated by 90.degree. with respect to one another, and are subsequently optically connected with one another.

Abstract: A detector device for the directionalized detection of laser radiation has a plurality of individual optics, which together can measure radiation throughout a defined total angle of detection. Each individual optical system comprises a fiber optic guide with a corresponding light concentrator, which has a generally funnel-shaped, dynamically balanced design, tapered towards the end of the fiber optic guide. The funnel wall reflects inwardly and is shaped, so that the following condition is fulfilled:A.sub.K sin.sup.2 .theta..sub.max >A.sub.F sin.sup.2 .theta..sub.g.