Coset, Inc. has developed fiber optic communication components and their related application products and the demands for them are rapidly increasing worldwide. Coset, Inc. is a company which possesses the advanced technology of fiber optic communication devices, especially the pump laser module for optical amplifier, in Korea. Coset, Inc. also owns high technologies to produce any other active modules and passive components of fiber optic communication devices. Pump Laser Module, 155Mb/s, 2,5Gb/s, 10Gb/s packaging and SOA, PLC(AWG), Lensed Fibers, Collimator, etc., with advanced technologies and superior competitive in quality, volume production ability and prices.