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.

Abstract: An optical-fiber gyroscope of the Sagnac type consists of a fiber-optic loop and a 3.times.3 coupler, composed of three optically coupled fiber-optic guides, whereby a first fiber-optic guide of the 3.times.3 coupler is coupled to an optical radiation source and the two other fiber-optic guides of the 3.times.3 coupler are coupled on one end to one end of the fiber-optic loop and, on the other end, to a radiation detecting instrument. The first fiber-optic guide of the 3.times.3 coupler features a radiation detecting instrument on the end opposite the radiation source, with which interference-related variations in the light source, as well as in the 3.times.3 coupler, can be detected.