Current efforts at the Lawrence Berkeley Laboratory to improve the operationalsefficiency of fluorescent lamps are based upon novel techniques intended to reducesinternal resonance radiative transport losses. Such losses have been associated withsentrapment of resonance radiation in the optically thick positive column of thesmercury vapor discharge. Two promising techniques for entrapment reduction are providedsrespectively to selective mercury isotope enrichment and by the broadening of the hyperfinesstructure (hfs) of the resonance line lambda2537 via the Zeeman effect. These techniquesshave, thus far, led to fluorescent lamp UV production efficiency enhancements, respectivelysof about 6.8% and 7%.

Additional efforts to improve HID sources are in progress. Interesting metallicshalides have been combined with electrodeless arc technology to produce a laboratorysdischarge system operating with an efficacy exceeding 170 lumens per watt, and a colorsrendering index (CFI) of 52.