包含两个半导体光放大器的锁模光纤环形激光器数值研究

Numerical Study of A Mode-locked Fiber Ring Laser Consisting of Two SOAs

采用自再现理论,对一种包含两个半导体光放大器的锁模光纤环形激光器进行了数值研究.研究结果表明:为了提高谐波锁模输出脉冲的质量,调制半导体光放大器应当保持高直流偏置,对自发辐射信号进行调制并提供锁模脉冲克服腔损耗所需的增益,而此时的增益半导体光放大器则被低直流偏置充当增益补偿器维持较窄的净增益窗口;与之相反,为了获得振幅均衡的有理数谐波锁模输出脉冲,调制半导体光放大器则应当偏置在较低的电流上,而增益半导体光放大器应当保持较高的偏置电流以提供足够的常量增益克服腔损耗.此外,还必须提高注入光信号的峰值功率.

Based on the self-reproduction theory, a mode-locked fiber ring laser consisting of two semiconductor optical amplifiers （SOAs） was numerically investigated. The result shows that the quality of harmonic mode-locked pulse can be enhanced when the modulation SOA is dc biased on the high current modulates the spontaneous emission in the SOA and provides the gain, whereas the gain SOA is dc biased on the low current functions as gain compensator for obtaining a narrow net gain window. However, to realize pulse-amplitude equalization of rational harmonic mode locking, the condition that the modulation SOA is dc biased on the low current whereas the gain SOA is dc biased on the high current must be satisfied, besides, an erbium-doped fiber amplifier （EDFA） should be added to the experiment setup to enhance the optical-injection power output from the gain switch DFBLD.