采用Fabry-Perot半导体激光器作为全光时钟分频器件,利用光注入半导体激光器产生的非线性动力学特性,实现了光脉冲的重复速率在9.0 GHz到19.8 GHz范围内连续可调的全光时钟分频.同时利用半导体激光器速率方程,对脉冲光注入半导体激光器产生时钟分频进行了数值模拟.实验和模拟结果表明半导体激光器在光注入的驱动下处于一周期振荡状态,当一周期振荡的二次谐波频率接近脉冲光的重复速率时,其二次谐波和基频被脉冲光同时锁定,此时将输出频率为脉冲光重复速率一半的时钟信号.同时研究了波长失谐量和注入光功率对时钟分频的影响.
All-optical time division was obtained in the frequency range from 9.0GHz to 19.8GHz.Nonlinear dynamics of a Fabry-Perot laser diode subjected to external optical injection is applied for all-optical clock division.The research results indicate that semiconductor laser subjected to external light injection performs period-one oscillation.We obtain the clock division of the signal pulses when the second harmonic frequency of the period-one oscillation approaches the repetition rate of the signal pulse,and the second harmonic and the fundamental frequency of the period-one oscillation were locked by the signal pulses simultaneously.Numerical simulation was performed on the all-optical time division with signal pulse injection using the rate equation of the semiconductor laser.The simulation result is in good agreement with the experiment.Phase noise level of the divided clock is observed to be smaller than-90 dBc/Hz over a frequency detuning range of 1.5GHz by changing the repetition rate of signal pulses under the fixed wavelength detuning value and input signal pulse power.