Soltani Mohammad, Ilchenko Vladimir, Matsko Andrey, Savchenkov Anatoliy, Schlafer John, Ryan Colm, Maleki Lute
Opt Lett. 2016 Sep 15;41(18):4375-8. doi: 10.1364/OL.41.004375.
Crystalline whispering gallery mode (WGM) electro-optic resonators made of LiNbO and LiTaO are critical for a wide range of applications in nonlinear and quantum optics, as well as RF photonics, due to their remarkably ultrahigh Q(>10) and large electro-optic coefficient. Achieving efficient coupling of these resonators to planar on-chip optical waveguides is essential for any high-yield and robust practical applications. However, it has been very challenging to demonstrate such coupling while preserving the ultrahigh Q properties of the resonators. Here, we show how the silicon photonic platform can overcome this long-standing challenge. Silicon waveguides with appropriate designs enable efficient and strong coupling to these WGM electro-optic resonators. We discuss various integration architectures of these resonators onto a silicon chip and experimentally demonstrate critical coupling of a planar Si waveguide and an ultrahigh QLiTaO resonator (Q∼10). Our results show a promising path for widespread and practical applications of these resonators on a silicon photonic platform.
由铌酸锂（LiNbO）和钽酸锂（LiTaO）制成的晶体回音壁模式（WGM）电光谐振器，因其具有显著的超高品质因数（>10）和大电光系数，在非线性光学、量子光学以及射频光子学等广泛应用中至关重要。对于任何高产量且稳健的实际应用而言，实现这些谐振器与平面片上光波导的高效耦合至关重要。然而，在保持谐振器超高品质因数特性的同时，证明这种耦合一直极具挑战性。在此，我们展示了硅光子平台如何克服这一长期存在的挑战。具有适当设计的硅波导能够实现与这些WGM电光谐振器的高效且强耦合。我们讨论了这些谐振器在硅芯片上的各种集成架构，并通过实验证明了平面硅波导与超高品质因数钽酸锂谐振器（Q ∼ 10）的临界耦合。我们的结果为这些谐振器在硅光子平台上的广泛实际应用展示了一条充满希望的途径。
