大功率半导体激光器高效率设计

河北工业大学

硕士学位论文

大功率半导体激光器高效率设计

姓名：杜伟华

申请学位级别：硕士

专业：物理电子学

指导教师：陈国鹰;杨红伟

20081101

河北工业大学硕士学位论文

大功率半导体激光器高效率设计

摘要

由于具有较高的输出功率和功率转换效率，大功率半导体激光器被广泛应用于泵浦固体激光器、激光加工、打印、光存储、光通讯及激光医疗等领域。功率、效率和可靠性是衡量半导体激光器性能的三个关键性指标。提高激光器的功率转换效率可以使激光器输入相同电流时输出更大的光功率，同时对于降低散热系统能耗、提高激光器光电特性、延长激光器寿命、提高可靠性以及节约运转费用有着非常重要的意义。效率的提高依赖于材料结构及其质量、芯片设计与器件制作工艺。

本课题基于器件的设计及其工艺的优化提高808nm大功率半导体激光器的功率转换效率。本文首先从理论上详细分析影响808nm大功率激光器效率的各个因素，然后以理论分析和计算机模拟为基础进行材料选择，波导层和包层使用AlGaAs材料，并且波导层采用大光腔结构，量子阱层使用AlGaInAs材料；在芯片制作方面，通过进行激光器的腔面反射率的设计，得出了最大的功率转换效率与腔长、腔面反射率的关系，选用了合适的腔面反射率进行腔面镀膜；在封装方面，鉴于微通道载体是目前解决连续工作大功率半导体激光器阵列散热问题的主要手段，因而采用微通道载体解决散热问题，通过计算机模拟，进行了微通道载体设计，同时对烧结工艺进行了优化。

通过对808nm大功率激光器进行深入研究，最终研制的808nm大功率半导体激光器微通道阵列，连续工作状态下，最高功率超过100W，功率转换效率达到56.7%，实现了项目指标。

关键词：功率转换效率，大光腔，应变量子阱，腔面反射率，烧结，微通道载体

i

大功率半导体激光器高效率设计

ii

DESIGN OF HIGH EFFICIENCY HIGH POWER

SEMICONDUCTOR DIODE LASER

ABSTRACT

Due to higher output power and power conversion efficiency, semiconductor laser diodes

have been widely used in pumping solid state lasers, laser processing, printing, optical storage, optical communication and laser medical treatment and so on. Output power, power conversion efficiency and reliability are three key factors scaling the semiconductor laser diodes performance. Improving the efficiency can output higher light power for the same current. Furthermore, it means great sense for reducing system energy cost, improving laser diodes photoelectric character and reliability, prolonging laser diodes lifespan and saving running expense. The improvement of efficiency depends on material structure design and quality, chip design and manufacturing technics.

In this paper we pay our attention to improving power conversion efficiency through laser diode design and technical optimization. Firstly, we analyze the factors theoretically that influence power conversion efficiency of 808nm semiconductor laser diodes in detail. Then the material with AlGaAs broad waveguide layer, AlGaAs cladding layer and AlGaInAs strain quantum well layer is grown, basing on our theoretical analysis and computer stimulation. Through cavity facet reflectivity design, we have obtained the relationship between the maximum power conversion efficiency and cavity facet reflectivity. In order to obtain the highest power conversion efficiency, we choose proper cavity facet reflectivity to make mirror coating. The last but not the least, considering that using microchannel heatsink is a main way to solve the problem of heat dispersing, we design microchannel heatsink through computer stimulation, and improve die-bonding technics.

Through our research on 808nm high power laser diode array, power has reached above 100W and power conversion efficiency has reached up to 56.7% at continuous wave operation. Our project object has been achieved.

KEY WORDS：power conversion efficiency, large optical cavity, strain quantum well, cavity facet reflectivity, die-bonding, microchannel heatsink