The A end of an optical module, typically the transmitting (Tx) end, should be connected to the corresponding receiving (Rx) port on the opposite device, ensuring proper fiber type and secure insertion.

Correct Placement

1. Identify the A End (Transmitting Side) The A end of an optical module usually corresponds to the transmitting interface (Tx), which emits the optical signal. The opposite end, B, is the receiving interface (Rx) that detects incoming light .
2. Match Fiber Type and Connector Ensure that the fiber optic cable matches the module type: single-mode modules with single-mode fibers and multimode modules with multimode fibers. Also, check the connector type (LC, MPO, etc.) to ensure compatibility .
3. Anti-Static Precautions Always wear anti-static gloves or wrist straps when handling the module to prevent electrostatic discharge (ESD) damage. Avoid touching the gold contacts or optical interfaces directly .
4. Insertion Procedure
   • Align the module with the front panel or on-board socket.
   • Insert the module gently until you feel a slight click or vibration, indicating it is locked in place.
   • Close the handle ring if present, and gently pull to verify it is fully seated. The module should not be removable without disengaging the latch .
5. Connection to Fiber After the module is securely inserted, connect the fiber patch cord to the A end (Tx) and the corresponding B end (Rx) on the other device. Ensure the fiber is clean and free of dust to prevent signal loss .
6. Verification Check the module's digital diagnostic monitoring (DDM) or status LEDs to confirm proper operation. The A end should emit light, which can sometimes be observed as a faint red glow for visible wavelengths, but never look directly into the fiber . By following these steps, the A end of the optical module will be correctly placed, ensuring reliable optical signal transmission and minimizing the risk of damage or performance issues.