The invention concerns a photoreflectance device (1) for characterising a rough surface comprising: - Means (2) for emitting a pump beam (3); - Means (8) for emitting a probe beam (11); - Means (14) for detecting the probe beam reflected by the surface; - An integrating sphere (13) capable of collecting the probe beam reflected by the surface, the integrating sphere comprising: - a first output (15) connected to the detection means (14), and disposed so as to receive a majority of the probe beam (11) reflected by the surface (4); - a second output (16) arranged so as to receive a majority of the pump beam (3) reflected by the surface.
