Guangtongxin yanjiu (Apr 2023)
The Optimal Design of New Electro-absorption Modulated Laser
Abstract
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 1 310 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.
