School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore, Singapore.
Singapore-MIT Alliance for Research and Technology (SMART), 1 CREATE Way #09-01/02 CREATE Tower, 138602, Singapore, Singapore.
Nat Commun. 2017 Nov 29;8(1):1845. doi: 10.1038/s41467-017-02026-w.
The integration of efficient, miniaturized group IV lasers into CMOS architecture holds the key to the realization of fully functional photonic-integrated circuits. Despite several years of progress, however, all group IV lasers reported to date exhibit impractically high thresholds owing to their unfavourable bandstructures. Highly strained germanium with its fundamentally altered bandstructure has emerged as a potential low-threshold gain medium, but there has yet to be a successful demonstration of lasing from this seemingly promising material system. Here we demonstrate a low-threshold, compact group IV laser that employs a germanium nanowire under a 1.6% uniaxial tensile strain as the gain medium. The amplified material gain in strained germanium can sufficiently overcome optical losses at 83 K, thus allowing the observation of multimode lasing with an optical pumping threshold density of ~3.0 kW cm. Our demonstration opens new possibilities for group IV lasers for photonic-integrated circuits.
将高效、小型化的 IV 族激光器集成到 CMOS 架构中是实现全功能光子集成电路的关键。然而，尽管取得了多年的进展，但迄今为止所有报道的 IV 族激光器由于其不利的能带结构而表现出不切实际的高阈值。具有根本改变能带结构的高应变锗已成为一种潜在的低阈值增益介质，但尚未成功证明来自这一看似有前途的材料系统的激光激射。在这里，我们展示了一种低阈值、紧凑型的 IV 族激光器，它采用了在 1.6%单轴拉伸应变下的锗纳米线作为增益介质。应变锗中的放大材料增益足以克服 83 K 时的光损耗，从而允许在光泵浦密度约为 3.0 kW/cm 时观察到多模激光激射。我们的演示为光子集成电路中的 IV 族激光器开辟了新的可能性。
