研究外部光注入半导体激光器的非线性物理特性, 用小信号分析方法分析了激光器的动力学行为。分析了外部光注入对半导体激光器的激光非线性频率啁啾影响, 给出了最大静态锁模公式, 理论上指出, 有外部光注入半导体激光器激光频率啁啾不再是传统意义上独立的半导体激光器线性啁啾, 它和外部注入光以及激光器所处的物理状态有着非常强烈的非线性关系, 并随着注入指数的增加而增强, 同时, 频差以及激光器光线宽增强因子也将起到一定的非线性影响作用。还给出了频差、最大锁模区域、激光分岔条件以及分岔的周期公式。详细地数值模拟了激光随外部光注入频差和注入参数变化所产生的由分岔进入混沌的动力学行为, 并数值分析了周期、三周期、多周期、混沌、充分发展混沌过程以及它们的旋转涡旋吸引子、频率、频谱、波形变化, 分别算出了最大李雅普诺夫(Lyapunov)指数、静态最大锁模区域和分岔周期, 数值给出激光随频率差变化分岔图, 逐步认清了该激光系统不稳定动力学行为以及频谱特点。

We study nonlinear physical characteristic of a semiconductor laser due to external optical injection. By small-signal analysis, we analyze dynamically behavior of the laser. Effect of the external light injection on nonlinear frequency chirping is analyzed and static maximal locking formula is given. We indicate theoretically that the frequency chirping of the optical injection laser is nonlinear related to the external injected light and the physical state of the laser while this nonlinear effect is promoted with adding the optical injection index. And the nonlinear frequency chirping can be nonlinearly affected by the frequency detuning and the linewidth broadening factor. Obviously, the nonlinear frequency chirping is physically different from the frequency chirping of the absolute laser. The frequency detuning, the maximal locking region, the bifurcation condition and bifurcation period formula are introduced. Dynamical behavior from bifurcation to chaos is numerically simulated with the external optical frequency detuning and the injection parameter, in detail. A single period, a tri-period, a multi-period, chaos, fully developed chaos and their rotating whirl attractors, frequencies, spectrums and waveforms are analyzed numerically, respectively. The maximum Lyapunov exponent, static maximal locking region and bifurcation period are calculated numerically, respectively. Bifurcation of the laser with the frequency detuning is numerically simulated. Unstable dynamical behavior and spectrum characteristic of the laser system is comprehended gradually.