基于λ/4相移分布反馈半导体激光器四波混频的THz波长转换特性研究

Theoretical investigation on THz wavelength conversion based on four-wave mixing in QWS-DFB-LD

利用耦合模方程,分析了基于λ/4相移分布反馈半导体激光器四波混频的波长转换特性.数值模拟表明:增大偏置电流、减小失谐量有利于扩展转换效率及消光比的动态范围,同时恶化了频率啁啾的动态范围;受激射效应影响,消光比及频率啁啾在弛豫振荡频率处达到极大值.通过合理选择系统参量,可以获得较理想的波长转换效果.该方案无需抽运光输入,可实现高速、宽带波长转换,在光通信系统中有一定的应用前景.

By using the coupled mode equations, the characteristics of THz wavelength converter based on four-wave mixing （FWM） in λ/4 phase-shifted distributed feedback laser diode （QWS-DFB -LD） are analyzed. The numerical simulation indicates that, larger biasing current and smaller detuning expand the dynamic range of conversion efficiency and extinction ratio, but worsen the frequency chirp. Due to the lasing effect, the peak modulation frequency of extinction ratio and chirp occur at the relaxation oscillation frequency. Good conversion characteristics can be obtained by selecting system parameters reasonably. This configuration would have potentials in optics communications because of its wide-band, high-speed and without pump input.