● Energy is injected into the erbium-doped fiber using 980 nm or 1480 nm pump sources, exciting ground-state erbium ions (Er³⁺) to higher energy levels; these ions then rapidly relax to a metastable state, thereby achieving a population inversion.
● When a 1550 nm signal light passes through the erbium-doped fiber, it triggers a stimulated emission process; this causes the metastable erbium ions (Er³⁺) to transition back to the ground state, releasing coherent photons that are identical to the signal light, thereby achieving exponential amplification of the signal power (in the small-signal regime).
● By employing erbium-ytterbium co-doped fibers combined with multimode pump combining technology, the saturated output power can be significantly enhanced (reaching power levels of several watts), thereby meeting the requirements of ultra-long-distance submarine cables, high-power CATV systems, and high-density transmission scenarios.
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Component |
Description |
|
Optical Isolator |
Conducts optical signals in one direction, prevents reflected light from causing self-oscillation, and protects the pump source and signal link stability. |
|
WDM Coupler |
Efficiently couples single-mode (SM) 980/1480 nm pump light and 1550 nm signal light into erbium-doped fiber for simultaneous energy and signal transmission. |
|
Er-doped Fiber |
The core gain medium that amplifies optical signals through energy level transition of erbium ions, determining the basic gain and noise performance. |
|
TAP Splitter |
Taps part of the optical signal in real time for power monitoring without affecting the main link, enabling system status visualization. |
|
Er-Yb Co-doped Fiber |
Improves pump absorption efficiency and saturated output power, suitable for high-power and long-haul amplification applications. |
|
Combiner |
Couples multi-mode (MM) pump light with pre-amplified signal light to realize high-power pump injection and enhance post-stage gain; widely used in high-power EYDFA designs. |
|
PumpLaserSource |
Provides excitation energy at 980 nm / 1480 nm: • 980 nm pump: low noise, high efficiency, suitable for medium- and short-haul applications • 1480 nm pump: higher saturation power, suitable for ultra-long-haul and submarine cable applications • Multi-mode pump: suitable for high-power amplification requirements |
980nm TEC-Cooled Pump Laser Diode
980nm Pump Diode Laser Module with Built-in Drive Circuits
C-band Erbium-doped Fiber Booster Amplifier
1457nm Raman Pump Laser Source
Q1: What are the advantages of 980 nm pumping and 1480 nm pumping respectively?
A1: Advantages of 980 nm pumping: high pump conversion efficiency and lower noise figure. It is the mainstream choice for low- to medium-power EDFAs, widely used in metropolitan area networks, access networks, and some data center interconnection scenarios.
Advantages of 1480 nm pumping: higher pump quantum efficiency and higher single-device output power, which significantly improve the saturated output power. It is the core pumping solution for high-power EDFAs, especially suitable for ultra-long-haul backbone networks, submarine optical cables, and high-capacity long-distance transmission scenarios.
Q2: What is the difference between single-mode and multi-mode EDFA?
A2: All mainstream EDFAs in the industry are single-mode EDFAs; there are no commercially viable multi-mode EDFA products. Single-mode EDFAs are designed specifically for single-mode fiber systems, matching the low-loss characteristics of single-mode fiber. They are mainly used for long-distance optical transmission and serve as core components in telecommunications and long-distance data center transmission. Multi-mode fiber is only suitable for short-distance transmission of around 100 meters, with high transmission loss and multipath dispersion. For gain compensation in short-distance scenarios, small semiconductor optical amplifiers (SOAs) are preferred instead of EDFAs.
Q3: Does wavelength range affect EDFA performance?
A3: Yes, wavelength affects EDFA performance. EDFAs mainly operate in the C-band and L-band, centered at approximately 1550 nm. Within the designed range, they provide flat gain and low noise; beyond the range, gain decreases and noise increases. To ensure EDFA performance, please ensure the amplifier’s wavelength range matches system requirements.
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