论文标题
基于二硝酸盐的超高Q赛车赛车
Ultra-high-Q racetrack microring based on silicon-nitride
论文作者
论文摘要
超高Q谐振器对于光学和微波光子学至关重要。到目前为止，在保持谐振器的紧凑尺寸的同时，提高Q因子仍然非常具有挑战性。本文中，我们提出并展示了具有均匀多模式SI3N4光子波导的超高Q硅氮化物（SI3N4）赛车谐振器。它由两个由两个多模式波导弯曲（MWB）连接的多模式直形波导组成。特别是，MWB基于修改的Euler曲线，并且将多模式直波导方向耦合器用于基本模式耦合，并避免在赛马场中令人兴奋的高阶模式。以这种方式，基本模式被激发并在具有超低损失的多模式赛车谐振器中传播。同时，它有助于实现紧凑的180°弯曲以减少芯片足迹。在本文中，通过将波导的宽度扩大到3μm，通过标准制造过程大大降低了基本模式的传播损失。结果表明，具有TE模式固有Q的超高Q谐振器为4.57*10^7，波导的相应传播损失仅为1.80 dB/m。据我们所知，这是环谐振器的最高Q值，到目前为止仅报告了2.226 mm的环长度。提出的超高Q SI3N4谐振器可用于具有较大操作带宽的微波光子过滤器和光电振荡器。
Ultra-high-Q resonators are fundamentally important to optics and microwave photonics. Up to now, it is still very challenging to boost the Q factor while maintaining a compact size for a resonator. Herein, we proposed and demonstrated an ultra-high-Q silicon-nitride (Si3N4) racetrack resonator with uniform multi-mode Si3N4 photonic waveguides. It consists of two multi-mode straight waveguides connected by two multi-mode waveguide bends (MWBs). In particular, the MWBs are based on modified Euler curves, and a multi-mode straight waveguide directional coupler is used for the fundamental mode coupling and avoid exciting higher-order modes in the racetrack. In this way, the fundamental mode is excited and propagates in the multi-mode racetrack resonator with ultra-low loss. Meanwhile, it helps to achieve a compact 180° bend to reduce the chip footprint. In this paper, the propagation loss of the fundamental mode is significantly reduced with standard fabrication process by broadening the waveguides width to as wide as 3μm. Results show that an ultra-high-Q resonator with an intrinsic Q of TE mode is 4.57*10^7, and the corresponding propagation loss of the waveguide is only 1.80 dB/m. To the best of our knowledge, this is the highest Q value of the ring resonator with only 2.226 mm ring length reported so far. The proposed ultra-high-Q Si3N4 resonator can be used to microwave photonic filters and optoelectronic oscillators with large operation bandwidth.
