Three port Optical Circulator allows light to move in only one direction. A signal entering to Port 1 will exit Port 2 with minimal loss, while a signal entering Port 2 will exit Port 3 with minimal loss. Light entering port 2 experiences a large amount of loss at port 1, and light entering port 3 experiences a large amount of loss at ports 2 and 1. Optical Circulators are non-reciprocal devices. Which means that any changes in the properties of the light caused by passing through the device are not reversed by traveling in the opposite direction.

Due to its high isolation and low insertion loss, optical Circulators are commonly used in advanced communication systems as add-drop multiplexers, bi-directional pumps, and chromatic dispersion compensation devices.

Figure 1. Circulator used to drop an optical channel from a DWDM system using a Fibre Bragg Grating.

As the Figure 1 shows: The input DWDM channels are coupled into Port 1 of the device with a FBG device connected to Port 2. The single wavelength reflected from the FBG then reenters the Circulator in Port 2 and is routed accordingly to Port 3. The rest of the signals move through the FBG and exit on

Figure 2. Circulator can often send optical signals through a single fibre in 2 directions.

Circulators could also be used to deliver optical signal in 2 directions down a single fibre. As the picture shows: A Circulator is located at each side of the fibre. Each Circulator functions to add a signal in one direction while removing the signal in the other. View the example in the Figure 2.

A standard Circulator operating in a 1550nm wavelength window usually has insertion loss of about 0.8dB, which is slightly higher than an isolator because of its more complex optical structure. The isolation value is on the order of -40dB and the directionality is often better than -50dB.

Characteristics

• Low Back Reflection
• High Extinction Ratio
• Low Insertion Loss
• High Return Loss

Applications

• DWDM system
• Add-Drop Multiplexing
• Fibre Amplifier
• Fibre Sensor
• Chromatic Dispersion Compensation Devices
• Fibre Bragg Grating

Optical Circulators can be used to achieve bi-directional optical signal transmission over a single fibre. Optical Circulators is widely used in WDM networks, polarization mode dispersion, chromatic dispersion compensation, optical add-drop modules (OADM), optical amplifiers, OTDR and fibre sensing applications. FS offer 3/4 Ports Polarization-Insensitive optical Circulator and 1310/1550/1064 Polarization-Maintaining (PM) optic Circulators. Our fibr opetical Circulators can provide high isolation, very low insertion loss, low polarization dependent loss (PDL), low polarization mode dispersion (PMD), and excellent environmental stability. Any other wavelengths, without or with any connector can customize according to your requirement.

Note:

1. Wavelength: FS can customize any other wavelengths according to your requirement.

2. Length: The default length for the cable is 1M. FS could also provide 0.5M,0.8M,1.5M, 2.0M, etc.

3. Connector: Each port of the Circulator could be with any connector such as FC/LC/SC/ST, etc.

Please contact us by email to sales@fs.com or call at +1-253-277-3058 if you have any requirement for it. For more information, please visit fs.com.