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，设计制作了一种新型的波长开关。在10 nm波长转换的情况下，波长转换效率高达-5dB。2-ps脉冲序列进行波长转换，无失真。该装置也可用作光学共轭器。光相位共轭器放置在40公里标准光纤链路的中间。利用光相位共轭器补偿了链路的二阶色散，实现了2ps光脉冲串的传输。作为四波混频技术在半导体光放大器中的又一应用，我们基于傅立叶合成器技术构建了一种超短光脉冲发生器。将两种不同波长注入到半导体光放大器中，产生四个波长分量，其中相位关系固定。通过调整这些元件的幅度和相位，我们可以产生113GHz， 1.8ps的光脉冲串。

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.