(Optional) Checking Optical Power

The following table describes comparison between the transmit optical power of 50 Gbps optical modules and damaged optical power threshold at the receive end:

Optical Module Type

Maximum Average Transmit Optical Power

Minimum Average Transmit Optical Power

Damaged Optical Power Threshold at the Receive End

Description

50GBASE-FR

3

-4.1

5.2

The damaged optical power threshold is greater than the maximum average transmit optical power, posting low self-loop risks.

50GBASE-LR

4.2

-4.5

5.2

50GBASE-ER

6.6

0.4

-2.4

The damaged optical power threshold is 9dBm lower than the maximum average transmit optical power and 2.8dBm lower than the minimum average transmit optical power, posing high self-loop risks. In this case, an optical attenuator must be configured for self-loop.

For applications of the 50 Gbps optical module supporting a distance of 40 km:

  1. To ensure that the optical module runs stably for a long time, adjust the receive optical power of the optical module to a value lower than -4 dB. According to the IEEE 802.3 standard, if the receive optical power of the optical module exceeds -2.3 dB, the optical module may be permanently damaged.
  2. Before connecting to the optical module, use an optical power meter to measure the receive optical power (P). If P is less than -4 dB, the optical module can be directly connected. If P is greater than -4 dB, add an optical attenuator at the receive end to ensure that the receive optical power is less than -4 dB. Alternatively, add an optical attenuator (no less than 10 dB is recommended) before the interconnection, and then adjust the optical attenuator based on the site requirements to prevent the optical module from being damaged.
  3. If a loopback occurs on the pigtail of the optical module or the optical module is connected for a short distance, an optical attenuator must be added. It is recommended that the optical attenuator be no less than 10 dB.
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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