InP基2μm波段分布反馈量子阱激光器制备研究

Facing the key scientific issues of fabricating InP-based distributed feedback(DFB) quantum well lasers emitting at 2μm region, which have potential applications in many areas, the project will carry out the research on fabrication of InP-based 2μm-region DFB quantum well lasers grown by MOCVD, combined with the research basis in material growth of large lattice-mismatch InAs/InP quantum wells as well as laser fabrication the applicant has had. The research work will be mainly placed on the following aspects including laser structure design and epitaxial growth, device fabrication as well as their performances testing and analyses. By these study, impacts of device structures and material properties on the laser output characteristics can be clarified and the electro-optical conversion efficiency can also be improved, realizing the breakthrough from material property to device performence. Through the implementation of this project we finally hope to provide new ways and new techniques for our country in developing high-performance mid-infrared semiconductor lasers with independent intellectual property rights.

本项目针对2μm波段分布反馈（DFB）量子阱激光器的潜在巨大应用需求以及其研制过程中所面临的关键科学和技术问题，结合申请人在2μm波段InAs/InP大晶格失配量子阱材料外延生长及激光器制备方面的研究基础，开展基于MOCVD的InP基2μm波段DFB量子阱激光器制备技术和相关机理研究。重点研究2μm波段DFB量子阱激光器的结构设计和外延、器件制备工艺及性能测试分析，澄清材料性能、器件结构以及工艺对激光器输出特性的影响，发展提高器件电光转换效率的新机制，从而实现从材料到器件性能的突破。为发展我国具有自主知识产权和规模化应用前景的高性能中红外半导体激光器提供新思路和新技术。

由于成本低、适合于大规模生产，InP基2微米波段量子阱激光器在气体探测，生物医疗，空间通信等领域具有广泛的应用前景，是目前半导体激光器领域的研究热点。本项目以实现高性能InP基2微米波段分布反馈量子阱激光器为目标，开展了基于MOCVD的InAs/InP量子阱激光器材料外延生长及器件制备应用研究，并已取得如下研究成果：.1、通过在较低温度下（470-510℃）进行量子阱有源区材料的外延生长，获得了光学与晶体质量较高的In0.53Ga0.47As势垒层（隔离层）材料。.2、通过优化有源区材料V/III比，在510℃条件下得到了晶体与光学质量较高的三层In0.82Ga0.18As/InP量子阱材料，并且通过对阱层厚度的调节，实现了PL波长在1.95-2.02微米范围连续可调。.3、优化二次外延生长条件，利用InP保护层和V族分段保护法很好的保持光栅形貌并减少上包层中的掺杂剂向上波导层和有源区的扩散.4、利用comsol等模拟仿真手段优化DFB激光器器件的结构参数，并采用全系曝光和传统光刻及刻蚀技术制备了高性能InGaAs量子阱脊波导DFB激光器，最大输出功率达到10.46mW，波长范围在2000nm-2008nm可调。室温100mA连续注入下，发光波长为2005.75nm，边模抑制比高达49dB。.5、通过采用更大应变的纯InAs材料作为量子阱材料，在更低的470℃生长温度下，得到了室温PL波长在2.1微米处的高质量二层InAs/InP量子阱材料.6、采用正台型脊条结构，制备了发光波长位于2.1微米的均匀结构耦合脊激光器阵列，输出光之间成功实现相干耦合.7、通过在耦合脊激光器阵列中引入啁啾脊条结构和边缘非注入区，成功抑制最高阶超模的激射，并实现了基超模激射。脉冲5A注入下，器件最大输出功率达到521mW，远场中心主峰半宽仅9.44°。