一种新型电吸收调制激光器的优化设计

The Optimal Design of New Electro-absorption Modulated Laser

针对传统选择性区域生长叠层双有源区电吸收调制激光器(SAG-DSAL-EML)在高频调制环境下的响应速度问题以及改善其远场发散角特性,文章提出利用掺铁掩埋技术对电吸收调制激光器(EML)结构进行优化,设计了InGaAsP/InP材料1310 nm掺铁掩埋结构的SAG-DSAL-EML并制作样本芯片,新型SAG-DSAL-EML有源区变为台面结构,并在其两层外延生长掺铁InP层。同时,利用先进激光二极管模拟器(ALDS)软件和高频结构仿真(HFSS)软件对所设计掺铁掩埋结构的EML和调制器进行数值及仿真分析,结果表明,与传统多量子阱结构相比,SAG-DSAL-EML阈值电流减少了13%;与传统脊波导结构相比,掺铁掩埋结构的侧向限制能力提高52%,激光远场横纵角度之差降低了40%,具有更小的远场发散角;与传统PNPN掩埋结构相比,掺铁掩埋结构的调制器在-3 dB的响应带宽提高了约24%。对样本芯片进行测试,试验表明,SAG-DSAL-EML的阈值电流为14.5 mA,边模抑制比(SMSR)为45.64 dB,70 mA注入电流下,电吸收调制器-3 dB的响应带宽为43 GHz,满足高速激光通信的基本要求。

In order to solve the problem of response speed and improve the far-field divergence angle characteristics of the traditional Selective Area Growth-Duble Stack Active Laser-Electro-absorption Modulated Laser(SAG-DSAL-EML)in a high-frequency modulation environment,this paper uses the iron-doped buried technology to the Elector-absorption Modulated Laser(EML)structure was optimized,and the SAG-DSAL-EML with a 1310 nm iron-doped buried structure of InGaAsP/InP material designed and a sample chip fabricated.The active area of the new SAG-DSAL-EML a mesa structure,and the two layers of the SAG-DSAL-EML epitaxially grown InP layer.At the same time,the laser part and modulator part of the designed iron-doped buried structure EML are numerically and simulated by Advanced Laser Diode Simulator(ALDS),and High Frequency Structure Simulator(HFSS).The results show that compared with the traditional multiple quantum well structure,the threshold current of the SAG-DSAL structure laser is reduced by 13%ompared with the traditional ridge waveguide structure,the lateral confinement capability of the iron-doped buried structure is improved by 52%.The difference is reduced by 40%and has a smaller far-field divergence angle ompared with the traditional PNPN buried structure,the response bandwidth of the modulator with the iron-doped buried structure at-3 dB is increased by about 24%.The sample chip is tested,and the test shows that the threshold current of the laser is 14.5 mA,the Side-Mode Suppression Ratio(SMSR)is 45.64 dB response bandwidth of the electro-absorption modulator-3 dB is 43 GHz under the injection current of 70 mA,which meets the basic requirements of high-speed laser communication.