Coherent Technologies Inc., supplier of laser-based remote-sensing systems, will break ground for a new building at the Colorada Technology Center in Louisville, Colo., this morning. The new 65,000-square-foot facility is scheduled for completion this winter.   . . .   April S. Brown, professor of electrical and computer engineering and executive assistant to the president at Georgia Institute of Technology, has been appointed chair of the Department of Electrical and Computer Engineering at Duke University's Pratt School of Engineering. Brown's appointment begins July 1. She will succeed interim chair Hisham Massoud, who is also director of graduate studies and a professor of electrical and computer engineering.