Emitting power of an 80km optical module

Typical 80 km single-mode optical modules have a transmit power (TX power) in the range of approximately 0 dBm to +5 dBm, depending on the module type and wavelength.OverviewOptical modules designed for 80 km transmission operate over single-mode fiber (SMF) and usually use 1550 nm wavelengths for long-distance communication, as this wavelength minimizes fiber attenuation . The transmitter section often employs EML (Electro-absorption Modulated Laser) or DFB (Distributed Feedback) lasers, which provide sufficient optical power to reach 80 km without intermediate amplification .Typical TX Power Range10G SFP+ DWDM modules (80 km): TX power is generally around 0 dBm to +4 dBm .1G SFP CWDM modules (80 km): TX power is typically 0 dBm to +3 dBm .100G QSFP28 ZR4 modules (80 km): Each lane usually transmits at 0 dBm to +5 dBm . The exact TX power depends on the module design, wavelength, and whether the module is DWDM, CWDM, or standard single-channel SFP/SFP+.Key ConsiderationsReceiver Sensitivity: The RX sensitivity of the module determines the minimum optical power required at the receiver to maintain a low bit error rate. For 80 km links, RX sensitivity is typically around -8 dBm to -20 dBm, depending on data rate and modulation .Optical Power Budget: The power budget is calculated as TX power minus RX sensitivity. For 80 km SMF, a power budget of 10–15 dB is usually sufficient to overcome fiber attenuation (~0.2 dB/km at 1550 nm) and connector/splice losses .Safety and Standards: All modules comply with Class 1 laser safety standards, ensuring safe operation .Module Type: DWDM modules may have slightly lower TX power due to tighter wavelength control, while EML-based modules provide higher output for longer distances .SummaryFor an 80 km optical module, the emitting power typically ranges from 0 dBm to +5 dBm, with the exact value depending on the module type, wavelength, and data rate. Ensuring proper TX/RX matching and considering the optical power budget is essential for reliable long-distance communication .