A field emission light source die configured to emit UV light, comprising: - a field emission cathode comprising a plurality of ZnO nanorods formed on a substrate, the substrate being adapted for a modular manufacturing process, - an anode structure comprising: - a transparent structure, - a first wavelength converting material arranged to cover at least a portion of the transparent structure, wherein the first wavelength converting material is arranged directly adjacent to the transparent structure, and the first wavelength converting material is configured to receive electrons emitted from the field emission cathode and to emit light of a first wavelength range, and - a conductive anode layer composed of a light reflective aluminum layer deposited onto the first wavelength converting material, wherein the conductive anode layer during use is arranged to have a voltage potential differing from the field emission cathode, whereby the electrons emitted from the field emission cathode will pass through the conductive anode layer before being received by the first wavelength converting material, and - a circular or elliptical spacer structure arranged to: - encircle the plurality of nanorods, - set a predetermined distance between the anode structure and the field emission cathode, and - form a hermetically sealed and evacuated cavity between the anode structure and the field emission cathode. - a field emission cathode comprising a plurality of ZnO nanorods formed on a substrate, the substrate being adapted for a modular manufacturing process, - an anode structure comprising: - a transparent structure, - a first wavelength converting material arranged to cover at least a portion of the transparent structure, wherein the first wavelength converting material is arranged directly adjacent to the transparent structure, and the first wavelength converting material is configured to receive electrons emitted from the field emission cathode and to emit light of a first wavelength range, and - a conductive anode layer composed of a light reflective aluminum layer deposited onto the first wavelength converting material, wherein the conductive anode layer during use is arranged to have a voltage potential differing from the field emission cathode, whereby the electrons emitted from the field emission cathode will pass through the conductive anode layer before being received by the first wavelength converting material, and - a transparent structure, - a first wavelength converting material arranged to cover at least a portion of the transparent structure, wherein the first wavelength converting material is arranged directly adjacent to the transparent structure, and the first wavelength converting material is configured to receive electrons emitted from the field emission cathode and to emit light of a first wavelength range, and - a conductive anode layer composed of a light reflective aluminum layer deposited onto the first wavelength converting material, wherein the conductive anode layer during use is arranged to have a voltage potential differing from the field emission cathode, whereby the electrons emitted from the field emission cathode will pass through the conductive anode layer before being received by the first wavelength converting material, and - a circular or elliptical spacer structure arranged to: - encircle the plurality of nanorods, - set a predetermined distance between the anode structure and the field emission cathode, and - form a hermetically sealed and evacuated cavity between the anode structure and the field emission cathode. - encircle the plurality of nanorods, - set a predetermined distance between the anode structure and the field emission cathode, and - form a hermetically sealed and evacuated cavity between the anode structure and the field emission cathode.