A photoreflectance device for characterizing a rough surface includes a pump beam emitter to emit a pump beam; a probe beam emitter to emit a probe beam; a detector to detect the probe beam reflected by the surface; an integrating sphere to collect the probe beam reflected by the surface, the integrating sphere including: a first output connected to the detector, and disposed so as to receive a majority of the probe beam reflected by the surface; a second output arranged so as to receive a majority of the pump beam reflected by the surface.