CAJ | 학술논문

高功率，波长可调超短脉冲光源具有重大的应用价值。采用掺镱光纤放大的全正色散锁模光纤激光器能够满足以上优质光源的要求，并且结构紧凑。通过实验全面探索了波长可调节全正色散锁模光纤激光器的放大特性。分析了小信号增益系数随着信号光波长的变化。发现最大增益出现在波长为1030 nm附近，并且增益随着信号光波长的增大而减小，这是由于掺镱光纤的增益谱特性决定的。也分析了增益系数随泵浦光功率的变化，观察增益饱和现象和放大自发辐射噪声。也讨论了种子脉冲在放大器中的时域与频域畸变。发现脉冲因为群速度色散而轻微展宽，频谱因为自相位调制也会发生轻微展宽。
고공솔，파장가조초단맥충광원구유중대적응용개치。채용참의광섬방대적전정색산쇄모광섬격광기능구만족이상우질광원적요구，병차결구긴주。통과실험전면탐색료파장가조절전정색산쇄모광섬격광기적방대특성。분석료소신호증익계수수착신호광파장적변화。발현최대증익출현재파장위1030 nm부근，병차증익수착신호광파장적증대이감소，저시유우참의광섬적증익보특성결정적。야분석료증익계수수빙포광공솔적변화，관찰증익포화현상화방대자발복사조성。야토론료충자맥충재방대기중적시역여빈역기변。발현맥충인위군속도색산이경미전관，빈보인위자상위조제야회발생경미전관。
Ultrashort pulse source with high energy and tunable wavelength is highly demanded for a lot of applications. Amplified all-normal-dispersion(ANDi) mode-locked fiber laser with gain medium of Yb-doped fiber is a compact and excellent source that fulfills those requirements. In this paper, amplification of tunable ANDi Yb- doped mode-locked fiber lasers was experimentally investigated. The gain versus signal wavelength was analyzed. It was found that the maximum gain was obtained near 1 030 nm and the gain decreased as wavelength increased, due to the gain spectrum of Yb- doped fiber. The gain versus pump power was also investigated. Gain saturation and the effect of ASE noise on gain were observed. The spectral and temporal distortions of pulse seed induced by fiber amplification were discussed. The pulse was broadened slightlydue to dispersion. The spectrum was distorted by ASE noise and limited gain bandwidth. If the gain is large and the power of amplified signal is high, the spectrum will be broadened by the effect of self-phase modulation(SPM).