 Shares of Coherent Inc. rose 0.8 in premarket trading Tuesday, after the laser technology company after Lumentum Holdings Inc. proposed a higher buyout bid, which would top the latest unsolicited bid from II-VI Inc. , which Coherent deemed was superior to the previously agreed upon bid from Lumentum. Shares of Lumentum dropped 1.9 ahead of the open, while II-VI stock inched up 0.1. 