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. <EOS>