Polarization Insensitive Optical Circulator It’s a compact, highperformance components, with high isolation, low insertion loss, low PDL, high stability and reliability. It is widely used in combination with fiber gratings and other reflective components in DWDM systems, wavelength add/drop, high speed systems, bi-direction communication systems, dispersion compensation, EDFA application and optical time domain reflectometer (OTDR) measurements.