An agreement has been signed under which Dynasil Corp. of America of West Berlin, N.J., will acquire 100 percent of the stock of Evaporated Metal Films (EMF) Corp. of Ithaca, N.Y. Dynasil manufactures optical blanks from synthetic fused silica as well as optical components and systems. EMF, a producer of optical thin-film coatings, will continue to operate from its current facility as a Dynasil business unit.