A lighting device for adjusting the color temperature of white light emitted by a luminescent material is disclosed. The lighting device comprises: a luminescent material configured to emit white light when being exposed to electromagnetic radiation of a preselected wavelength range; at least one excitation unit configured to expose the luminescent material to electromagnetic radiation of a first wavelength range selected from the range of 230-330 nm; at least one excitation unit configured to expose the luminescent material to electromagnetic radiation of a second wavelength range, different from the first wavelength range, selected from the range of 300-600 nm; a metering unit configured to adjust the ratio of the irradiances of electromagnetic radiation of first wavelength range and of electromagnetic radiation of second wavelength range that is exposed on the luminescent material.