高功率1550 nm氧化限制型VCSEL设计与仿真

Design and Simulation for High-power 1550 nm Oxide-confinement VCSEL

1550 nm垂直腔面发射激光器具有良好的人眼安全性和透射性,但实现其高效率和高功率输出一直是难以解决的问题。以1550 nm氧化限制型垂直腔面发射激光器为研究目标,对不同结构、不同氧化孔径与输出特性关系进行仿真分析。随着氧化孔径增加,垂直腔面发射激光器芯片的激射波长发生红移现象,但氧化孔径从14μm继续增大时,激射波长几乎不红移。对两种不同氧化限制结构的芯片进行仿真,输出功率和转换效率对比结果表明单氧化层结构性能更好。在设计多结垂直腔面发射激光器时考虑有源区之间是否增加氧化层,最终发现两种氧化限制结构均在9μm孔径时具有较高的输出功率,单层结构100 mA时的输出功率约为177.55 mW,同时斜率效率也高达1.79 W/A,最大功率转换效率为10μm孔径时的37.7%,多层结构斜率效率更高达2.36 W/A。氧化限制型结构在多结垂直腔面发射激光器基础上进一步提升功率、效率等参数,可为高功率1550 nm垂直腔面发射激光器的输出特性优化提供参考。

Achieving high efficiency and power output for 1550 nm Vertical Cavity Surface Emitting Lasers(VCSEL)remains a challenging issue.In the content of VCSEL,optimizing the oxide aperture size has been shown to enhance output power and slope efficiency.Additionally,multi-junction has emerged as a promising approach to boost the VCSEL chip power.The integration of these two techniques for 1550 nm VCSEL has the potential to optimize their output characteristics.This study builds upon previous researches on 1550 nm multi-junction VCSEL and investigates their combination with oxide aperture structures.The primary focus is on output power,slope efficiency,and photoelectric conversion efficiency.Different structures with varying oxide aperture sizes are simulated and analyzed detailedly to achieve highpower VCSEL with improved performance.The differences in output characteristics between singlejunction VCSEL with and without an oxide aperture layer between the active region and N-type Distributed Bragg Reflector(DBR)were investigated before.The main comparison parameters are output power and slope efficiency.Two different oxide aperture structures are simulated and compared,the results show that VCSEL chips without an oxide aperture layer between the active region and N-DBR exhibit higher output power and slope efficiency.At an oxide aperture size of 11μm,a single-junction 30μm VCSEL demonstrates a threshold current of approximately 1 mA and an output power of about 57.2 mW.Furthermore,during the investigation,the simulation results can be indicated that as the oxide aperture size increases,the chip's lasing wavelength experiences a red-shift phenomenon,with a maximum red-shift of up to 6.5 nm.However,beyond an aperture size of 14μm,the lasing wavelength hardly red-shifts.To address this shift issue,the thickness of the spatial aperture layer is adjusted to tune the chip's lasing wavelength to around 1550 nm.Based on these findings,the paper delves into the exploration of multijunction VCSEL.Due to the unique structure of the active region in multi-junction VCSEL,the paper considers the feasibility to add an oxide aperture layer within the active region during chip design.The oxide aperture size is adjusted and simulations are conducted to compare the output power,slope efficiency,and photoelectric conversion efficiency between the two structures.The results show that both structures achieve higher output power at an aperture size of 9μm.For the single-layer structure,the output power reaches approximately 177.55 mW at 100 mA,with a slope efficiency of 1.79 W/A,and the maximum power conversion efficiency of 37.7%is achieved at a 10μm aperture size.The multi-layer structure exhibits even higher slope efficiency,reaching 2.36 W/A.The comparison of simulation results shows that although the proposed multi oxide layer structure can achieve the goal of improving power,the conversion efficiency is not higher as well,which is also related to the high applied voltage.The research in this paper demonstrates the potential of oxide aperture structures in further improving parameters such as power and efficiency for multi-junction VCSEL.The combination of oxide aperture integration and multi-junction structures can provide a reference for optimizing the output characteristics of high-power 1550 nm VCSEL,making them highly desirable for various applications in the fields of communications,sensing,and optical interconnects.