Optical attenuator CBO SFA21BK25 Singlemode 25 dB

The Optical attenuator CBO SFA21BK25 Singlemode 25 dB is an inline passive device designed to reduce optical power levels in singlemode fiber links by 25 dB. It is intended to stabilize signal strength and prevent receiver overload in telecom, datacom and fiber network installations. The compact form factor makes it suitable for integration into patch panels, equipment racks and test setups where precise attenuation is required without introducing active components.

Advantages

This singlemode attenuator provides accurate and stable 25 dB attenuation with minimal insertion loss beyond the specified attenuation. Being a passive component, it requires no power and contributes negligible maintenance overhead. The inline design ensures simple deployment in live links or test loops, while optical-quality connectors preserve signal integrity and minimize reflections. Its compact construction supports space-efficient installation in constrained rack or enclosure environments.

Suitable for

• Balancing optical link power in point-to-point singlemode networks
• Protecting receiver modules from excessive optical input during equipment upgrades or testing
• Temporary insertion during maintenance and commissioning of fiber links
• Laboratory and field testing where a fixed 25 dB attenuation is required

Key specifications

• Attenuation: 25 dB fixed value for singlemode fiber
• Fiber type: singlemode
• Form factor: inline attenuator suitable for patchcord integration
• Passive operation: no external power required
• Typical return loss: optimized to minimize back-reflection and preserve link performance
• Operating environment: suitable for standard indoor telecom and datacom installations

How to use

Install the attenuator inline between two singlemode fiber connectors by inserting it into the optical path, ensuring connectors are clean and properly mated. Verify connector types and polish grades are compatible before connection. For live networks, confirm that the reduced optical power at the receiving end meets system sensitivity requirements. During testing or commissioning, use an optical power meter and light source to measure link power levels before and after insertion to validate the expected 25 dB attenuation.

Recommendations

Inspect and clean fiber connectors prior to installation to avoid contamination-related loss. Avoid mechanical stress or sharp bends at the attenuator interface, and store the device in a dry, dust-free environment when not in use. When used in mission-critical links, perform power measurements after installation to confirm required signal margins.