What is EDFA?
Erbium Doped Fiber Amplifier is short for EDFA,which was applied in 90 s in the optical fiber transmission system and its popularization and application of optical fiber communication technology has brought a revolution.
EDFA is in small volume,low power consumption,easy to us.What’s more,it is convenient to install all kinds of application systems,such as SDH frame inside,CATV machine box,DWDM system frame.
The birth of Erbium Doped Fiber Amplifier is a revolutionary breakthrough.It makes possible for the long distance,large capacity,high speed optical fiber communication.The development of its research and application of optical fiber communication has important significance.In recent years,fiber optic CATV EDFA System especially 1500nm optical fiber CATV System is being rapidly develop in our country.Erbium Doped Fiber Amplifier has been widely used in optical fiber CATV system.Power amplifier allocated the optical output power of the transmitter again in the front end of the CATV system.Fiber optic trunk transmission is used for each direction.Power amplifier and power divider also can consider to reuse.From the branch of fiber backbone that far away from the front end,we can insert the Erbium Doped Fiber Amplifier to make up the branch loss.
As one of a functional modes of the Optical fiber amplifier system,there are generally two kinds of methods to insert the network management system.One is 232 c interface circuit with optical fiber amplifier to transfer parameters of the optical fiber amplifier and alarm information to the network management system,unified management,display and disposal.
Erbium Doped Fiber is the core of EDFA.It use quartz optical fiber as a substrate material,and mixed with a proportion of Er3+.When a pump into the Erbium Doped Fiber,Er3+ will be aroused to high level.Because the Er3+ on the high level is short life,it will work in the form of non – radiative transition to a higher level soon.And the population inversion is between the energy level and low level distribution.Due to the energy difference between the two energy levels is equal to 1550 nm of photon energy,it can be stimulated radiation of 1550nm light only.
Advantages of CATV EDFA
EDFA is in the low noise,has the characteristics of good gain trace,large amplifier bandwidth,compatible with wavelength division multiplexing (WDM) systems,with high efficiency,work performance is stable,mature technology and so on and so forth.It is very popular in the modern long-distance high-speed optical communication system.
◆ Good character：
Before the pump generally use 980 nm,after level pump use 1480 nm.Minimizing the NF of EDFA by reasonable optimization to make the system access excellent CNR.
◆ Reliability：
Use 1 u 19 “standard rack, built-in high-performance switching power supply.It can work in 85∽265 vac enterprise voltage.DC48V power supply (reservations) can be an option,too.Chassis cooling can be automatic temperature control.
◆ Intuition：
This machine contains a microprocessor to monitor the working state of the pump laser, LCD displays the working parameters.
◆ Network management model：
Options type monitoring transponder to ensure to meet the national standard with the SCTE HMS standards, which can realize network management monitoring.
◆ Adjustable output optical power：
Output optical power can be changed to -3dB.
◆ The power plug type：
Aluminum structure plug type switching power supply.Be good for heat dissipation and replacement.
Structure Diagram
The key technical indexes
| Items | EDFA |
| Wavelength(nM) | 1545~1555 |
| Optical input power(dBm) | -5~+10 |
| Nominal input power(dBm) | +3 |
| Noise coefficient(dB) (+3 dBm,@1550nM) | 3.8~5.5 |
| Gain Flatness(dB) | <±0.3 |
| Optical output power stability(dB) | <±0.5 |
| Polarization sensitivity(dB) | <0.2 |
| Polarization Mode Dispersion(ps) | <0.5 |
| Light fittings(IN/OUT) | FC/APC |
| Pump work quantity(N) | 1∽3 |
| Saturation output power(dBm) | 13∽25 |
| Power supply(Vac) | 115~265（Power plug） |
| Power supply(Vdc) | 48（Power plug） |
| Operating temperature(℃) | 0~50 |
| Size(mm) | 44×482.6×387 |
