Patent ID: 8779363

Claim:
An optical sensor of chemical species comprising: a fluorescent source of incoherent infrared radiation comprising a chalcogenide glass matrix doped by rare earth ions; at least one infrared radiation detector provided with a spectrum selector device and arranged to detect the radiation emitted by said fluorescent source, a chemical species detection zone being provided between said source and said detector; and a pumping source emitting visible or infrared radiation adapted to excite the fluorescence of said rare earth ions; the sensor being characterized in that: it also comprises a first optical fiber coupling said pumping source to said fluorescent source; and in that said infrared radiation detector comprises: a fluorescent element arranged to be illuminated by the infrared radiation emitted by said source after passing through said chemical species detection zone, said fluorescent element comprising a rare earth ion doped chalcogenide glass matrix in which said ions, when in a first excited state, are capable of absorbing a photon of said radiation, and then of emitting a photon at a shorter wavelength; a second pumping source emitting visible or infrared radiation adapted to take said rare earth ions into said first excited state; and a second optical fiber coupling said fluorescent element to a radiation detector.