Plasma light source

A light source powered by High Frequency energy, the source having:

• an enclosure of lucent material, the enclosure having:
• a sealed void therein,
• a fill in the void of material excitable by High Frequency energy to form a light emitting plasma therein,
• a High Frequency energy-enclosing Faraday cage surrounding the enclosure, the Faraday cage being:
• at least partially light transmissive for light exit from the plasma crucible and the Faraday cage having:
• two end portions and an outer sleeve between the end portions, and
• an antenna arranged within the Faraday cage for transmitting plasma-inducing, High Frequency energy to the fill, the antenna having:
• a connection extending outside the Faraday cage for coupling to a source of High Frequency energy;
• wherein:
• a High Frequency energy-barrier cylindrical inner sleeve is arranged within the outer sleeve, the inner sleeve being:
• at least partially light-transmissive for light passage therethrough and being,
• connected electrically at one end to one end portion of the Faraday cage and
• defining a launching gap at the other end with the other end portion of the Faraday cage,
• the enclosure is arranged within at least one of the inner sleeve and the launching gap and
• the antenna is arranged between the inner and the outer sleeves;
• whereby High Frequency energy introduced between the sleeves via the antenna can be launched via the gap into the inner sleeve for excitation of the plasma and radiation of light through the sleeves and out of the source.