Optical setup

Before connecting

• Use high-quality APC connectors everywhere. Back-reflections must be as low as possible because the amplifiers work bidirectionally on one fiber.

• Clean all connectors.

Balancing the two directions

Compensate for any difference in insertion loss between the two directions with fixed attenuators, so that the input powers at both sides of the amplifier are equal, ideally within ±1 dB.

Choosing input power

The amplifier can deliver +13 dBm (C-band) and +10 dBm (L-band), but we recommend lower levels, especially when coherent data channels share the fiber.

Working near the optimal-gain point, ignoring external filter loss:

• Prepare an input level of about −22 to −23 dBm at the amplifier.

• Expected gain is about 23 dB (C-band) and 22 dB (L-band), giving about 0 to +1 dBm at the output.

Worked example (illustrative). The incoming signal at the WEST port is −12 dBm. To reach −22.5 dBm, insert a 10.5 dB attenuator (use 10 dB plus 0.5 dB or the nearest available value). With 23 dB gain, the output at the EAST port is about +0.5 dBm. Verify the same on the reverse direction.