A ROPA (Remote Optical Pumping Amplifier) is a remote optical amplifier subsystem designed to meet the needs of long-haul optical transmission in areas without relay power. It provides a power compensation solution for ultra-long-haul single-span transmission.

Application Scenarios

It is primarily used in the following environments:

• When connecting mainland China with islands, or when crossing uninhabited areas such as deserts, swamps, forests, and snow-capped mountains, optical relay site maintenance and power supply are extremely difficult.
• In remote areas, due to geographical constraints, relay site installation is difficult, sites are sparsely distributed, and distances between sites are long.
• In densely populated areas, it reduces the number of intermediate sites, lowering network construction and maintenance costs.

For ultra-long span link scenarios with higher span loss requirements, a bypass remote pumping solution can be added to the ROPA remote pumping system.

System Functionality

The remote pumping subsystem consists of two main components: the RPU (Remote Pumping Unit) and the RGU (Remote Gain Unit).

• RPU: Composed of a Raman board, multi-order Raman, and ROP, its primary function is to generate pump light. The ROP is installed at the site.

– The ROP generates pump light in the 1480nm band and the multi-order Raman circuit (ERPC) generates pump light in the 1276nm band, providing energy for signal light amplification in the transmission fiber.

– It enables long-distance, wide-bandwidth, low-noise, distributed online signal light amplification.

– It can monitor pump light power, temperature control current, and pump current.

– It features automatic pump power lock, accepts commands from the main control board to turn the pump source on and off, separates signal light, reports various performance indicators and alarms, and provides pump laser protection.

• RGU: Uses erbium-doped fiber as the gain medium and is installed on the optical cable line.

– It connects to the gain medium in the optical fiber link via an optical cable junction box. Because the pump source is located at the terminal site, the pump light reaches the gain medium via a section of transmission fiber. Therefore, the gain unit is also called a remote gain unit.