电泵浦紫外等离子体纳米激光器的研究

Smaller lasers have important applications in nano-photonics and photonic circuits. However, the minimum size of conventional semiconductor lasers is restricted by the diffraction limit. Plasmonic lasers based on the surface plasmon polaritons can breakthrough the diffraction limit, realizing nanometer scale coherent sources. But plasmonic lasers are usually achieved with a high threshold due to their large metallic and scattering losses. Although ultraviolet nano-lasers have wild applications, electrically pumped ultraviolet nano-lasers have never been achieved, because of higher loss in the region. A metal-insulator-semiconductor structure has been proposed to reduce the metallic loss. While the scattering loss caused by unevenness of the interface is still large. In view of the above problems, we plane to design and construct a ZnO nanowire @SiO2/Ag structure, which employing the nature semiconductor nanowire with smooth surface to achieve smooth interface, thus reducing the scattering loss. Electrically pumped ultraviolet plasmonic nano-lasers operating at room temperature may be realized in this structure. This project will promote the development of plasmonic nano-lasers towards practical applications.

微型激光器在纳光子学和光子电路方面有重要的应用，而传统半导体激光器的最小尺寸受到衍射极限的限制。基于表面等离子体激元的纳米激光器利用表面等离子体对电磁场的约束性，可以突破衍射极限实现纳米尺度的相干光源，但是受到高金属损耗和散射损耗的限制，其阈值往往很高。紫外波段纳米激光器有广泛的应用前景，但由于该波段损耗更加严重，导致电泵浦的紫外等离子体纳米激光器仍然未能实现。金属-绝缘体-半导体结构能有效降低金属损耗，但由界面不均匀引起的散射损耗依然严重。针对以上问题，本项目设计并构建ZnO纳米线@SiO2/Ag芯壳结构，利用天然形成的半导体纳米结构具有光滑表面的特点，能够实现平滑的界面降低金属损耗，因此有望实现室温电泵浦紫外等离子体纳米激光器。本项目的开展将推动等离子体纳米激光器向实用化发展。

微型激光器在纳光子学和光子电路方面有重要的应用，而传统半导体激光器的最小尺寸受到衍射极限的限制。基于表面等离子体激元的纳米激光器利用表面等离子体对电磁场的约束性，可以突破衍射极限实现纳米尺度的相干光源，但是受到高金属损耗和散射损耗的限制，其阈值往往很高。紫外波段纳米激光器有广泛的应用前景，但由于该波段损耗更加严重，导致电泵浦的紫外等离子体纳米激光器仍然未能实现。金属-绝缘体-半导体结构能有效降低金属损耗，但由界面不均匀引起的散射损耗依然严重。.我们制作了p-GaN/MgO/ZnO/MgO/Ag结构，在该结构中首次实现了超低阈值（70.2 A/cm2）的紫外波段电泵浦等离子体激光器。该结构中，ZnO被用作增益介质以匹配Ag表面等离子体频率，另外ZnO大的激子束缚能也有利于等离子体激光器的实现。电磁场被限制在MgO介质层中传播，具有较高的自发辐射耦合因子，同时减少了金属中的欧姆损耗。上述结果促进了电泵浦等离子体激光器的发展，也为改善ZnO基紫外激光器性能提供了一种可行方法