High-Q microresonators on 4H-silicon-carbide-on-insulator platform for nonlinear photonics

The realization of high-quality(Q)resonators regardless of the underpinning material platforms has been a ceaseless pursuit,because the high-Q resonators provide an extreme environment for confining light to enable observations of many nonlinear optical phenomenon with high efficiencies.Here,photonic microresonators with a mean Q factor of 6.75×10^(6)were demonstrated on a 4H-silicon-carbide-on-insulator(4H-SiCOI)platform,as determined by a statistical analysis of tens of resonances.Using these devices,broadband frequency conversions,including second-,third-,and fourth-harmonic generations have been observed.Cascaded Raman lasing has also been demonstrated in our SiC microresonator for the first time,to the best of our knowledge.Meanwhile,by engineering the dispersion properties of the SiC microresonator,we have achieved broadband Kerr frequency combs covering from 1300 to 1700nm.Our demonstration represents a significant milestone in the development of SiC photonic integrated devices.

Soliton formation and spectral translation into visible on CMOS-compatible 4H-silicon-carbide-oninsulator platform

Recent advancements in integrated soliton microcombs open the route to a wide range of chip-based communication,sensing,and metrology applications.The technology translation from laboratory demonstrations to real-world applications requires the fabrication process of photonics chips to be fully CMOS-compatible,such that the manufacturing can take advantage of the ongoing evolution of semiconductor technology at reduced cost and with high volume.Silicon nitride has become the leading CMOS platform for integrated soliton devices,however,it is an insulator and lacks intrinsic second-order nonlinearity for electro-optic modulation.Other materials have emerged such as AlN,LiNbO_(3),AlGaAs and GaP that exhibit simultaneous second-and third-order nonlinearities.Here,we show that silicon carbide(SiC)--already commercially deployed in nearly ubiquitous electrical power devices such as RF electronics,MOSFET,and MEMS due to its wide bandgap properties,excellent mechanical properties,piezoelectricity and chemical inertia--is a new competitive CMOS-compatible platform for nonlinear photonics.High-quality-factor microresonators(Q=4×10^(6))are fabricated on 4H-SiC-on-insulator thin films,where a single soliton microcomb is generated.In addition,we observe wide spectral translation of chaotic microcombs from near-infrared to visible due to the second-order nonlinearity of SiC.Our work highlights the prospects of SiC for future low-loss integrated nonlinear and quantum photonics that could harness electro-opto-mechanical interactions on a monolithic platform.

Photonic crystal nanobeam cavities based on 4H-silicon carbide on insulator

The 4H-silicon carbide on insulator(4H-SiC0l)has recently emerged as an attractive material platform for integrated photonics due to its excellent quantum and nonlinear optical properties.Here,we experimentally realize one-dimensional photonic crystal nanobeam cavities on the ion-cutting 4H-SiC0l platform.The cavities exhibit quality factors up to 6.1×10^(3)and mode volumes down to 0.63×[λ/n]^(3)in the visible and near-infrared wavelength range.Moreover,by changing the excitation laser power,the fundamental transverse-electric mode can be dynamically tuned by 0.6 nm with a tuning rate of 33.5 pm/mW.The demonstrated devices offer the promise of an appealing microcavity system for interfacing the optically addressable spin defects in 4H-SiC.