808nm腔面光栅波长锁定半导体激光器的研究

Aiming at the existing problems of traditionally wavelength-locked laser diodes (LDs), that outer wavelength lock system strongly depends on environment, and inner grating fabrication process results in contamination and introduces defects in the epilayers due to regrowth, a novel method to realize wavelength lock by grating coating on the facet of LD is proposed in this project. Firstly, research on the mechanism of facet grating will be carried out, and a new model of grating coupling will be built by exploring the relationship between periode, duty cycle and coupling coefficient of grating. Secondly, research on the spin coating of photoresist on the facet of LD will be carried out. A tool of supporting chip for spin coating will be designed to solve the problem of hard spin coating on the facet of LD, by exploring the effect of press, size, weight of supporting tool on the thickness and uniformity of photoresist. Additionally, research on laser holography technology will be carried out. The conditions of holography lithography will be optimized to achieve high quality photolithography patterns. Furthermore, research on the coating process of facet grating will be carried out. By optimizing coationg process conditions and parameters of grating films, and improving quality of grating films, the uniform coating of high quality grating on facet of LD should be realized. So that the researches in this project will provide theoretical basis and technical reserve on the application of nano fabrication process in the field of semiconductor devices.

本项目针对半导体激光器传统的波长锁定方案中由于外腔波长锁定系统对外部环境的依赖，和内置光栅方案中由于芯片进行二次外延生长会产生污染和引进缺陷等问题，拟采取在边发射半导体激光器有源区的出光面制作光栅的一种全新的半导体激光器波长锁定方案。研究腔面光栅的工作机理，探索腔面光栅的周期、占空比与光栅耦合系数之间的关系，建立一种新的腔面光栅耦合模型。开展半导体激光器腔面匀胶技术的研究，设计支撑芯片进行匀胶工艺的芯片夹具，探索芯片夹具的压力、尺寸、重量对光刻胶厚度和均习性等参数的影响，解决半导体激光器腔面上难以匀胶的问题。开展全息光刻技术的研究，优化全息光刻条件，以获得高质量的光刻图形。开展腔面光栅膜层沉积工艺技术的研究，优化膜系材料沉积的工艺条件和参数，提高膜层的沉积质量，实现高质量光栅材料在腔面上的均匀沉积，为微纳米工艺技术在半导体器件领域的应用提供理论基础和技术储备。

本项目针对半导体激光器传统的波长锁定方案中由于外腔波长锁定系统对外部环境的依赖，和内置光栅方案中由于芯片进行二次外延生长会产生污染和引进缺陷等问题，采用在边发射半导体激光器有源区的出光面制作光栅的一种全新的半导体激光器波长锁定方案。腔面光栅半导体激光器是通过在半导体激光器有源区的后腔面上沉积增反膜，在前腔面上制作光栅，有源区内产生的光子就会在前、后腔面之间形成振荡，达到增益以后产生激光，并实现激光的波长锁定。开展了腔面光栅半导体激光器的工作原理的研究，完成了腔面增透膜和增反膜材料的选择、膜系结构的厚度、反射率、以及腔面光栅的阶数、周期、和占空比等参数的优化设计。设计了一种能够支撑芯片进行匀胶和光刻工艺的芯片夹具，使用芯片夹具开展了腔面匀胶技术的研究，优化光刻胶和稀释液的配比浓度、转速、时间等参数，实现对光刻胶厚度和均匀性的精确调控。开展了全息光刻技术制备光栅掩膜图形的研究，根据808nm腔面光栅半导体激光器腔面光栅结构的设计，计算光路系统参数并搭建全息光刻系统的光路，优化全息曝光条件，实现腔面光栅掩膜图形的制备。根据808nm腔面光栅半导体激光器腔面膜系结构的设计，开展了腔面膜层材料的沉积，优化膜层沉积工艺，精确控制膜层厚度，实现各膜层的透射率、反射率、带宽等指标能够满足808nm腔面光栅半导体激光器单纵模输出的性能要求。开展了808nm腔面光栅半导体激光器单管芯器件的制备与表征。制备的808nm腔面光栅半导体激光器单管芯器件（条宽100m，腔长2mm）实现了器件输出中心波长807.32nm，光谱半宽为0.36nm，15℃-45℃温度范围内波长随温度的漂移系数为0.072nm/℃，室温单管芯最大连续输出功率达到2.8W，阈值电流为0.49A，斜率效率为1.05W/A。测试结果表明808nm腔面光栅半导体激光器实现了单纵模输出。本项目在执行期间共计发表学术期刊论文13篇，学术会议论文5篇，授权发明专利3项，申请发明专利5项，培养硕士研究生14名。