Thermally isolated high intensity light source

A high intensity discharge light source comprising:

• a bulb having:
• a first end;
• a second end;
• a central region extending between said first end and said second end in a longitudinal direction;
• and
• an outer surface extending between said first end and said second end;
• a thermally insulative and optically transparent sleeve having an inner surface, said sleeve longitudinally aligned with and separated from said bulb outer surface by an insulating distance;
• a first spacer positioned adjacent to said bulb first end and between said bulb outer surface and said sleeve inner surface;
• a second spacer positioned adjacent to said bulb second end and between said bulb outer surface and said sleeve inner surface;
• wherein:
• said first spacer and said second spacer provides said insulating distance between said bulb outer surface and said sleeve inner surface, thereby forming an insulative volume around said bulb;
• and
• during use said bulb and surrounding insulative volume reach an elevated steady state operating temperature to maintain or enhance a spectral performance parameter.