An optical sensor configured for detecting electromagnetic beams ( F ) simulating bullets in a military tactical simulation, said optical sensor having a substantially laminar body having a front side and a rear side, said substantially laminar body comprising some overlapping layers, said layers comprising: - at least one channelling layer configured to convey and retain within electromagnetic beam ( F ) portions having an incidence angle to said channelling layer of less than 90°; - at least one refractive material layer configured for fragmenting the electromagnetic beams ( F ) that hit it and divert said fragments to said at least one channelling layer with an incidence angle of less than 90°; - at least one reflective layer arranged on the rear side of said laminar body to reflect electromagnetic beam ( F ) portions, that should cross said at least one channelling layer and said at least one refractive material layer , towards said at least one channelling layer and said at least one refractive material layer ; - at least one electromagnetic beam sensor coupled to said at least one channelling layer to receive its channelled electromagnetic beam portions, said optical sensor being characterized in that at least one first of said at least one channelling layer is disposed on the front side of the laminar body and interposed between said refractive layer and a source area of the electromagnetic beams ( F ). said substantially laminar body comprising some overlapping layers, said layers comprising: - at least one channelling layer configured to convey and retain within electromagnetic beam ( F ) portions having an incidence angle to said channelling layer of less than 90°; - at least one refractive material layer configured for fragmenting the electromagnetic beams ( F ) that hit it and divert said fragments to said at least one channelling layer with an incidence angle of less than 90°; - at least one reflective layer arranged on the rear side of said laminar body to reflect electromagnetic beam ( F ) portions, that should cross said at least one channelling layer and said at least one refractive material layer , towards said at least one channelling layer and said at least one refractive material layer ; - at least one electromagnetic beam sensor coupled to said at least one channelling layer to receive its channelled electromagnetic beam portions, - at least one channelling layer configured to convey and retain within electromagnetic beam ( F ) portions having an incidence angle to said channelling layer of less than 90°; - at least one refractive material layer configured for fragmenting the electromagnetic beams ( F ) that hit it and divert said fragments to said at least one channelling layer with an incidence angle of less than 90°; - at least one reflective layer arranged on the rear side of said laminar body to reflect electromagnetic beam ( F ) portions, that should cross said at least one channelling layer and said at least one refractive material layer , towards said at least one channelling layer and said at least one refractive material layer ; - at least one electromagnetic beam sensor coupled to said at least one channelling layer to receive its channelled electromagnetic beam portions, said optical sensor being characterized in that at least one first of said at least one channelling layer is disposed on the front side of the laminar body and interposed between said refractive layer and a source area of the electromagnetic beams ( F ). <EOS>