The invention relates to an illumination device with a light emitting device (1) and a light sensor (3) for optical feedback by online monitoring the light output. The light emitting device (1) and the light sensor (3) are arranged adjacent to each other and are at least partially covered by an optical coupling device (7) for coupling a part of the emit- ted light from the light emitting device (1) to the light sensor (3). Further, an optical attenuator (11) is provided between the optical coupling device (7) and the light sensor (3). The optical attenuator (11) can be adapted such that a linear photosignal of the light sensor (3) over the complete driving current range of the light emitting device (1) is achieved. This is advantageous since calibration efforts are minimized.
