Optical attenuator CBO SFA21BK4 Singlemode LC Simplex 4 dB

Optical attenuator CBO SFA21BK4 Singlemode LC Simplex 4 dB is a passive inline device designed for singlemode fibre networks. It features an LC simplex connector and a fixed 4 dB attenuation, providing precise reduction of optical power to protect sensitive receivers and to equalize signal levels across fibre links. The attenuator is suitable for installation in telecommunications, data centre patch panels and test setups where consistent optical loss is required.

Advantages

The attenuator offers a compact form factor with stable, repeatable attenuation and low insertion loss beyond the specified 4 dB reduction. Its LC simplex interface ensures compatibility with standard singlemode jumper cables and patch panels. As a passive component it requires no power and provides immediate attenuation without calibration, reducing risk of receiver saturation and facilitating signal balancing in multi-span links.

Suitable for

• Protecting optical receivers from high input power
• Balancing signal levels between transmitters and receivers in singlemode networks
• Temporary insertion for commissioning and maintenance tasks
• Use in test benches and measurement setups for controlled power reduction

Key specifications

• Fiber type: singlemode (SM)
• Connector type: LC simplex
• Attenuation value: fixed 4 dB
• Polarisation: non-polarising design suitable for standard singlemode operation
• Operating wavelength range: compatible with typical singlemode telecom wavelengths (e.g. 1310 nm / 1550 nm)
• Form factor: inline, compact attenuation module for patch panels and pigtail connections

How to use

Insert the LC simplex connector of the attenuator between the transmitting or receiving fibre jumper and the device requiring reduced optical power. Ensure connectors are clean before mating to prevent additional loss or contamination. The fixed 4 dB attenuation is applied immediately upon connection; no configuration or power supply is required. For rack or panel installations, route the fibre carefully to avoid sharp bends and secure the attenuator in the patching area to prevent strain on the connectors.

Recommendations

Prior to insertion, inspect and clean LC connectors with suitable fibre cleaning tools. Use the attenuator in environments within manufacturer-recommended temperature and humidity ranges and avoid exposure to direct mechanical stress. For systems where precise attenuation across a wide wavelength range is required, confirm optical budget margins and use a calibrated optical power meter to verify power levels after installation.