摘要
采用一级全息光栅和二步液相外延法研制出高稳定单纵模工作的1.55μm分布反馈(DFB)激光器.20℃时连续工作阈值电流I_(th)为40mA,单纵模光功率为7.5mW.在70℃高温和 1GHz正弦信号调制下保持边模抑制比(SMSR)大于 30dB的单纵模工作,最高SMSR大于38dB.线宽△v为30MHz.单纵模产率Y_(SLM)48％.70℃环境下通电100mA连续24小时老化后,阈值电流变化率△I_(th)/I_(th)(20℃)≤10％,SMSR未劣化.该DFB激光器首次在国内实用化五次群光纤通信系统(传输码635Mb/s、RZ)上实现70.7km普通光纤无中继传输.
Highly stable single longitudinal mode (SLM) operation 1.55μm distributed feedback(DFB) lasers have been developed by means of the two-step liquid phase epitaxy (LPE) andfirst-order grating.The CW threshold current is typically about 40mA (20℃), and the lightoutput power for stable CW SLM operation is 7.5mW. SLM operation with a side-mode-sup-pressionratio (SMSR) of 30dB from 20℃ to 70℃ and under 1GHz sinewave modulation canbe sustained.The maximum SMSR is 38dB.Spectral linewidth is 30MHz. SLM yield is 48%.After a 70℃-100mA-24hrs prescreened, the rate of increase in threshold current is less than10%, no degradation of spectra is observed.A 635Mbit/s(RZ) error-free transmission is ac-complished over a 70.7km fiber length by the DFB laser for the first time in China.
