Coherent Inc. of Santa Clara, Calif., has purchased Molectron Detector Inc. of Portland, Ore., for $11.5 million, forming the technology business unit, Coherent Molectron. The acquisition will provide customers with a broad range of laser test and measurement equipment. Molectron's power and energy measurement technology and commitment to research and development will support Coherent's next-generation products for the scientific and commercial markets. The unit, along with Molectron's senior management team, will remain in Portland.