AlGaN基深紫外激光器在军事领域和国民经济领域都有重要的应用前景。然而由于高Al组分AlGaN低维量子材料位错密度高、量子阱有源区增益低、光和载流子的分别限制难以实现等关键问题，导致深紫外激光器无法在电注入条件下工作。本申请项目拟结合纳米图形化AlN类横向外延和渐变超晶格插入技术进行位错过滤和应力调控，降低量子阱有源区材料的位错密度。通过低Si掺杂的AlxGa1-xN/AlyGa1-yN超晶格应力插入层实现对量子阱价带的调控，获得更多解理面腔镜反射损耗小的TE模式光，同时缓解电流阻塞效应。设计优化不同掺杂方式的阶梯量子阱有源区结构，减小量子限制斯塔克效应，增加电子-空穴波函数的空间重叠率，提高辐射复合速率。结合大光腔强折射率条形波导结构和高反射率p型电极，最终制备出低发散角、低损耗、低阈值电流的280 nm AlGaN基深紫外激光器。

AlGaN-based deep ultraviolet (DUV) lasers have significant application prospects in the military field and national economy. However, the high dislocation density of AlGaN materials with high Al content, low gain of multi-quantum wells (MQWs) active region, and the separately confinment of photons and carriers impose restrictions on the realization of electrically pumped deep ultraviolet lasers. In this program, both nanopatterned AlN templates and grading supperlattices inserted layer will be introduced to filter dislocation and relax strain and low dislocation density MQWs active region can be obtained. The low Si-doped AlxGa1-xN/AlyGa1-yN superlattices inserted layer will play an indispensable role in manipulating the valence band to realize that more TE mode photon can be radiated in MQWs which will cause low reflection loss of the cleavaged cavity mirror, and that current crowding effect can be weakened. Furthermore, step MQWs with different doping methods will be introduced to reduce the quantum-confined Stark effect (QCSE), to improve the spatial overlap of electron - hole wave functions, and to improve the carrier recombination rate. Finally, AlGaN-based DUV lasers with low divergence angle, low loss and low threshold current can be fabricated by combining the strong refractive index strip waveguide with large optical cavity structure and high reflectivity p-type electrode.