The present invention relates to a device and method for detecting light allowing retrieval of a physiological parameter of a user carrying said device. To improve the efficiency of light capturing, the device (1, 2, 3, 4) comprises a light source (10) arranged for emitting light of at least a first wavelength into tissue of the subject, a wavelength converter (20) arranged for receiving at least part of the emitted light after interaction of the emitted light with the tissue and for converting the received light into at least a second wavelength different from the first wavelength, and a light sensor (30) arranged for receiving light converted by said wavelength converter.