Large TE polarized optical gain from AlInN-delta-GaN quantum well for ultraviolet lasers
Large TE polarized optical gain from AlInN-delta-GaN quantum well for ultraviolet lasers
复制标题
用于紫外激光器的 AlInN-delta-GaN 量子阱的大 TE 偏振光学增益
DOI：
--
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Jing Zhang
中科院分区：
文献类型：
--
作者：
Cheng Liu;Y. Ooi;Jing Zhang
波长(λ) < 300 nm的紫外激光器在自由空间通信、水/空气净化和生化试剂检测等领域有着重要的应用。传统上，AlGaN量子阱（qw）被广泛用作紫外激光器的有源区。然而，λ ~ 250 ~ 300 nm的高效电注入中紫外激光器仍然是非常具有挑战性的，因为相应的AlGaN qw由于在重空穴（HH）和晶体场分裂（CH）子带之间存在价子带交叉而遭受严重的带混合效应，这将导致在该波长范围内的光学增益非常低。因此，在这项工作中，我们提出并研究了使用AlInN材料体系作为中紫外激光器的替代方案。利用AlInN-delta-GaN QW进行纳米结构工程，以实现主导导带- HH子带跃迁以及优化的电子-空穴波函数重叠。与Al0.82In0.18N层晶格匹配的超薄δ - gan层的插入将使波函数强烈地定位于有源区域的中心，从而在λ~ 250 ~ 300 nm处获得较大的横向电（TE）极化光学增益（gTE）。从我们的发现来看，使用AlInN-delta-GaN QW，在~ 255 nm发射增益介质时，te偏振光学增益比传统AlGaN QW提高了~ 3倍。可以通过改变δ层厚度来调节峰值发射波长，同时保持较大的TE增益。具体来说，在λ ~ 280 ~ 300 nm范围内获得了gTE ~ 3700 cm-1，这是传统AlGaN QW活性区非常具有挑战性的。
Ultraviolet (UV) lasers with wavelength (λ) < 300 nm have important applications in free-space communication, water/air purification, and biochemical agent detection. Conventionally, AlGaN quantum wells (QWs) are widely used as active region for UV lasers. However, high-efficiency electrically injected mid-UV lasers with λ ~ 250-300 nm are still very challenging as the corresponding AlGaN QWs suffer from severe band-mixing effect due to the presence of the valence sub-band crossover between the heavy-hole (HH) and crystal-field split off (CH) sub-bands, which would result in very low optical gain in such wavelength regime. Therefore, in this work, we propose and investigate the use of AlInN material system as an alternative for mid-UV lasers. Nanostructure engineering by the use of AlInN-delta-GaN QW has been performed to enable dominant conduction band – HH sub-band transition as well as optimized electron-hole wave function overlap. The insertion of the ultra-thin delta-GaN layer, which is lattice-matched to Al0.82In0.18N layer, would localize the wave functions strongly toward the center of the active region, leading to large transverse electric (TE) polarized optical gain (gTE) for λ~ 250- 300 nm. From our finding, the use of AlInN-delta-GaN QW resulted in ~ 3-times enhancement in TE-polarized optical gain, in comparison to that of conventional AlGaN QW, for gain media emitting at ~ 255 nm. The peak emission wavelength can be tuned by varying the delta layer thickness while maintaining large TE gain. Specifically, gTE ~ 3700 cm-1 was obtained for λ ~ 280-300 nm, which are very challenging for conventional AlGaN QW active region.
影响因子：
2.6
作者：
Martens, Martin;Mehnke, Frank;Kneissl, Michael
通讯作者：
Kneissl, Michael