The 4 Ports 1480nm Singlemode Polarization Insensitive Optical Circulator is a high-performance non-reciprocal passive device designed to direct light sequentially from Port 1 → Port 2 → Port 3 → Port 4 with minimal insertion loss and high isolation. Operating at 1480 nm, it is optimized for FTTx, PON systems, and optical communication networks, where precise signal routing and low back reflection are essential.