Excel Continuum Corp., a subsidiary of Excel Technology Inc. of East Setauket, N.Y., has purchased Continuum, Hoya Photonics Inc.'s scientific division, along with its subsidiaries in Germany, France and Japan. The Santa Clara, Calif.-based division delivers high-energy pulsed and tunable laser technology to the scientific and commercial markets. Excel, a supplier of laser systems and electro-optical components, had not participated in the pulsed laser market before. The cash transaction totals approximately $13 million.