基于泵浦功率限制下的光放大PPM发射系统优化

Optimization of optical amplification PPM transmission system based on pump power limitation

为了研究光通信中发射端在不同脉冲位置调制(PPM)阶数下脉冲信号平均发射功率变化的问题,基于掺镱光纤放大器理论分析模型,采用两级放大系统,通过优化增益光纤长度对不同调制阶数下的光发射系统平均输出功率特性进行了仿真研究。仿真结果表明:在泵浦功率限制下,不同调制阶数下的最优增益光纤长度会受泵浦功率的影响而变化,随着调制阶数增大,最优增益光纤长度也增大,但对平均输出功率的影响较小;当固定光发射系统硬件条件不变时,不同调制阶数下的信号平均输出功率不相等,128PPM的平均发射功率只有4PPM的51%左右,发射功率损失近3 dB。

In order to study the change of average transmitting power of pulse signal in different order of pulse position modulation(PPM)at the transmitter end in optical communications,this paper uses a two-stage amplification system based on the theoretical analysis model of Yb-doped fiber amplifiers.By optimizing the length of gain fiber,the average output power characteristics of optical emission system with different modulation orders are simulated.The simulation results show that under the limitation of pump power,the optimal gain fiber length under different modulation orders will be affected by the pump power.As the modulation order increases,the optimal gain fiber length also increases,but it has little effect on the average output power;when the hardware conditions of the fixed optical transmission system are unchanged,the average output power of the signals at different modulation orders is not equal,the average transmission power of 128PPM is only about 51%of 4PPM,and the transmission power loss is nearly 3 dB.