PLAINVIEW, N.Y., June 2 -- Aeroflex Inc. will produce $6.6-million worth of microelectronic thin film subassemblies for use in fiber optic interfaces. The company expects to deliver the order over the next 12 months. According to Aeroflex its microelectronics group was awarded the contracts from a leading fiber optics systems manufacturer.   These new contracts are further evidence that our enabling technology satisfies the growing demand for advanced OC-48 and OC-192 fiber optic products, said John Buyko, senior vice president for Aeroflex microelectronics. Our previous investments in capacity and capability have positioned Aeroflex to support our customers' stringent requirements for these advanced fiber optic products.