The Isolator Polarization Beam Combiner / Splitter is a compact device which provides both polarization beam combining and optical isolation in one integrated component. The most common application is to combine the light of two pump lasers into a single fiber to double the pump power to an Erbium-Doped Fiber Amplifier (EDFA) or a Raman Amplifier. Due to IPBC / IPBS has extremely low insertion loss it can improve the amplifier performance.