A recent test of optical coatings at MIT may lead to increased interest in solid-state light sources for next-generation microchip lithography. MIT staff scientist Vladimir Liberman conducted the study to evaluate the state of excimer-grade fused silica, CaF and MgF, for 193-nm lithography systems. He added to these optical materials a nonlinear material proposed for a solid-state lithography source: lithium triborate. He discovered that the lithium triborate exhibited longevity comparable to top-quality excimer-grade fused silica after transmitting 500 million pulses at 10 to 15 mJ/cm2. The results could lead to the development of an optical train compatible with 193-nm technology.