Abstract: A station for locating through laser rays an object likely to diffuse back a part of the incident laser ray, wherein the optical emitter and receiver devices consist of one single device comprising, in the direction of emission, a device for separating the emitted and retrodiffused rays, an optical device converting the emitted parallel beam of small diameter into a divergent beam and a telescope adapted to collimate the divergent beam received from the optical device into a parallel beam of larger diameter, the retrodiffused beam travelling that path in the direction reverse from the emitted beam, the invention being usable for detecting in particular forest fire smokes.