Optical isolators are devices that allow the transmission of laser beams emitted from a laser diode to travel in only one direction. When built into high power laser modules such as Fiber Laser sources for material processing, they protect the laser diode by intercepting light reflected back from the materials. Shin-Etsu’s optical isolators have very low transmission loss and excellent thermal lens characteristics which are based on new Faraday-rotator materials and provide very compact packages. Shin-Etsu Chemical has implemented vertical integration of its entire production system for optical isolators, covering every process from the processing of the raw material.