Ultra-fast optical fiber communication systems using third-order optical nonlinearity in semiconductor optical amplifiers

从理论上研究了半导体光放大器的四波混频特性。在此基础上，设计并制作了一种新型的波长开关。在波长转换为10 nm的情况下，波长转换效率高达-5db。对2ps的脉冲串进行了无失真的波长转换，该器件还可用作光学共轭器。光学相位共轭器放置在40公里标准光纤链路的中途。利用光学相位共轭器对链路的二阶色散进行了补偿，成功地传输了2ps的光脉冲序列。作为四波混频在半导体光放大器中的另一种应用，我们构建了基于傅里叶合成技术的超短光脉冲发生器。将两个不同波长的光注入半导体光放大火，产生四个波长分量，它们之间的相位关系是固定的。通过调整这些分量的幅度和相位，可以产生113 GHz、1.8ps的光脉冲序列。

We theoretically study four-wave mixing characteristics of semiconductor optical amplifiers. Based on the analyzes, we design and fabricate a new type of wavelength switch. The wavelength conversion efficiency was as high as -5dB in the case of 10-nm wavelength translation. A 2-ps pulse train was wavelength-converted without distortion.This device is also used as an optical conjugator. The optical phase conjugator is placed at the midway of a 40-km standard fiber link. The second-order dispersion of the link was compensated by the optical phase conjugator, and we succeeded in the transmission of 2-ps optical pulse trains.As another application of four-wave mixing in semiconductor optical amplifiers, we construct an ultra-short optical pulse generator based on the Fourier synthesizer technique. Two different wavelengths are injected to the semiconductor optical amplifire, and four wavelength components are generated, among which the phase relation is fixed. By adjusting the amplitude and phase of these components, we could generate 113GHz, 1.8ps optical pulse trains.