The 4 Ports C+L 1528~1610nm Singlemode Polarization Insensitive Optical Circulator is a high-performance non-reciprocal passive optical device that directs light sequentially from Port 1 → Port 2 → Port 3 → Port 4, ensuring precise and efficient unidirectional signal transmission. Designed to operate over the C+L wavelength band (1528–1610 nm), it provides broadband operation, low insertion loss, high isolation, and excellent return loss, making it an ideal solution for next-generation optical communication systems.