Abstract: Optical device and optical component part for the targeted reproduction of light emitted by LED light sources (6). The optical device comprises at least two component parts, a first optical component part (10) in the form of a solid waveguide and another component part for connection to the LED light source (6). In a system of Cartesian co-ordinates, the first optical component part (10) has a length in the y direction shorter than or equal to its length in the z direction and shorter than or equal to its length in the x direction. An envelope of the first optical component part (10) projected in an x-y plane forms essentially a rectangle. Proceeding from an x-y plane, the optical component part (10, 10?) tapers in the z direction to maximum ¼ of the largest width measured along y (By, max), with any design of the y-z flanks of the optical component part (10, 10?).