Opt Lett. 2023 Feb 1;48(3):735-738. doi: 10.1364/OL.476517.
Despite having achieved drastically improved lasing characteristics by harnessing tensile strain, the current methods of introducing a sizable tensile strain into GeSn lasers require complex fabrication processes, thus reducing the viability of the lasers for practical applications. The geometric strain amplification is a simple technique that can concentrate residual and small tensile strain into localized and large tensile strain. However, the technique is not suitable for GeSn due to the intrinsic compressive strain introduced during the conventional epitaxial growth. In this Letter, we demonstrate the geometrical strain amplification in GeSn by employing a tensile strained GeSn-on-insulator (GeSnOI) substrate. This work offers exciting opportunities in developing practical wavelength-tunable lasers for realizing fully integrated photonic circuits.
尽管通过利用拉伸应变实现了激光特性的显著改善，但目前将大量拉伸应变引入 GeSn 激光器的方法需要复杂的制造工艺，从而降低了激光器在实际应用中的可行性。几何应变放大是一种简单的技术，可以将残余和小的拉伸应变集中到局部和大的拉伸应变量中。然而，由于在传统的外延生长过程中引入了固有压缩应变，该技术不适用于 GeSn。在本信中，我们通过使用拉伸应变的 GeSn 层上的绝缘体（GeSnOI）衬底来证明 GeSn 中的几何应变放大。这项工作为开发用于实现全集成光子电路的实用波长可调谐激光器提供了令人兴奋的机会。
