The authors build on previous experience in the optimization of white-light sources based on combinations of narrow-band spectra. They extend those concepts by using delta-function spectra to study the prospects of future optimal laser-based sources. The optimization process is based on a trade-off between the color rendering properties and the luminous efficacy of the radiation. Optimal solutions for four, five and six delta-function spectra with correlated color temperatures in the 3000 to 5500 K range are presented and analyzed. White-light sources with these properties would likely find wide acceptance in numerous lighting applications.