Optical Wavelength Conversion Unit. STM-64 Transmitting Optical Wavelength Conversion Unit with FEC Function, страница 18

Performances reported by D16 board include: input optical power.

Erbium doped fiber amplifier (EDFA) is an essential part of DWDM system. The optical amplifier unit in OptiX BWS 320G system of Huawei provides three kinds of optical amplifier board: WBA (optical booster amplifier), WLA (optical line amplifier) and WPA (optical preamplifier).

1. Principle

WBA is usually installed at the transmitting end of OptiX BWS 320G system and is generally called power amplifier. It is used to amplify the transmitted optical power and compensate the insertion loss of optical passive devices. The main requirement of DWDM system on the optical booster amplifier is large output optical power. According to the module functions, WBA board of OptiX BWS 320G system performs the functions of input optical power detection, output optical power detection, and automatic gain control, as shown in Figure 3-14.

Figure 3-14 Function block diagram of WBA board

2. Functions

Power gain of WBA for respective wavelength optical signals: gain of the power amplifier currently adopted in OptiX BWS 320G system is shown in Table 3-15.

Input optical power range: the input optical power range of the optical amplifier unit WBA is shown in Table 3-15.

Table 3-15 Parameters of WBA/WLA/WPA

n  Optical signals of the 32 channels can be amplified simultaneously (channel spacing being 0.8 nm) with the working wavelength range of 1535~1561nm.

n  Flat gain in the working wavelength range, flatness <2dB.

n  Gain lock function is available. When one or several channels are added or removed, the normal operation of other channels will not be affected; at the same time transient control function is also available, so in OptiX BWS 320G system when channels are added or removed, burst of error codes on the existing channels can be basically avoided.