Cloutier Sylvain G, Kossyrev Pavel A, Xu Jimmy
Division of Engineering and Department of Physics, Brown University, Providence, Rhode Island, USA.
Nat Mater. 2005 Dec;4(12):887-91. doi: 10.1038/nmat1530. Epub 2005 Nov 20.
Persistent efforts have been made to achieve efficient light emission from silicon in the hope of extending the reach of silicon technology into fully integrated optoelectronic circuits, meeting the needs for high-bandwidth intrachip and interchip connects. Enhanced light emission from silicon is known to be theoretically possible, enabled mostly through quantum-confinement effects. Furthermore, Raman-laser conversion was demonstrated in silicon waveguides. Here we report on optical gain and stimulated emission in uniaxially nanopatterned silicon-on-insulator using a nanopore array as an etching mask. In edge-emission measurements, we observed threshold behaviour, optical gain, longitudinal cavity modes and linewidth narrowing, along with a collimated far-field pattern, all indicative of amplification and stimulated emission. The sub-bandgap 1,278 nm emission peak is attributed to A-centre mediated phononless direct recombination between trapped electrons and free holes. The controlled nanoscale silicon engineering, combined with the low material loss in this sub-bandgap spectral range and the long electron lifetime in such A-type trapping centres, gives rise to the measured optical gain and stimulated emission and provides a new pathway to enhance light emission from silicon.
人们一直在持续努力实现硅的高效发光，希望将硅技术的应用范围扩展到全集成光电子电路中，以满足高带宽芯片内和芯片间连接的需求。已知通过量子限制效应，理论上可以实现硅的增强发光。此外，在硅波导中也证明了拉曼激光转换。在此，我们报告了使用纳米孔阵列作为蚀刻掩膜的单轴纳米图案化绝缘体上硅中的光学增益和受激发射。在边发射测量中，我们观察到阈值行为、光学增益、纵向腔模和线宽变窄，以及准直远场图案，所有这些都表明存在放大和受激发射。亚带隙1278nm发射峰归因于A中心介导的捕获电子与自由空穴之间的无声子直接复合。可控的纳米级硅工程，结合该亚带隙光谱范围内的低材料损耗以及此类A型捕获中心的长电子寿命，产生了所测量的光学增益和受激发射，并为增强硅的发光提供了一条新途径。
