The halogen lamps are just a variation of the incandescent using a halogen gas to permit higher operating temperatures without much evaporation. They should produce more light with the same energy consumption, because radiation rises with the 4th power of temperature. Chlorophyll is green so it probably uses something other than green for photosynthesis. The process is organic, so it is probably not a resonant absorption like ionization. It is a very pure orange and about as efficient as electric light can get because the sodium is easy to ionize and no wavelength shifting is necessary.
Plants look putrid under it, however.