Optical circulators of Fibrain Directivity family are passive optical devices, usually having 3 or 4 ports, that are used for switching signals between the ports in a given order. It is a way of achieving high directional isolation and low-loss transmission between specified pairs of ports. The most frequently used type of optical circulator is the 3-port version. It transmits the signal from port 1 to port 2 and from port 2 to port 3, blocking the transmission between other port pairs. The 3-port circulator is usually used for switching from a piece of link that uses bidirectional transmission in one fiber to a piece with standard bidirectional transmission in two fibers.The circulators are available in versions optimized for 1310, 1490, 1550, 1590, and 1625 nm windows. They are delivered with a report containing attenuation and isolation values in the operation band and with labeled ports and direction of transmission.
Λc ± 30 nm
|IL||≤ 0.8 dB|
|Directional isolation||≥ 40 dB|
|RL||≥ 55 dB||≥ 50 dB|
|PDL||≤ 0.15 dB|
|Max optical power||500 mW|
|PMD||< 0.1 ps|
|Temp. of operation||from – 50C to + 750C|
|Temp. of storage||from – 400C to + 850C|
Notice: Parameters listed in the table refer to components without connector terminations
Optical circulators with output fibers with 250/900 µm coating have a 5.5x50 mm pipe casing with a serial naumber printed on the pipe with an indicated direction of transmission.