Compact Racetrack Resonator on LiNbO3

A small all-pass racetrack resonator with a large free spectral range (FSR) is proposed and designed with a 600-nm-thick LiNbO3-on-insulator (LNOI) optical waveguide. It is shown that intermode crosstalk happens in LiNbO3 waveguide bends because more than one modes are generated from the anisotropy of LiNbO3. A sharp LNOI waveguide arc-bend is realized theoretically by choosing the geometrical parameters optimally to achieve constructive interference between the excited modes. This is very useful to realize compact resonators on LNOI. In particular, a novel racetrack resonator with a straight coupling region as well as Euler-bends is proposed. Here the narrow straight waveguides are introduced in the coupling region so that sufficient coupling between the access waveguide and the resonator is achieved within a short length. Euler-bends are introduced to avoid mode-mismatching at the junction between the straight-bent sections. For the designed LNOI racetrack resonator with an equivalent bending radius of 18 μm, the free-spectral range (FSR) is as large as 5.8 nm, and the Q-factor is 6.5 ×105 when assuming that the LNOI waveguide has a propagation loss of 1 dB/cm.

[1]  Yansong Yang,et al.  Ultra-efficient and fully isotropic monolithic microring modulators in a thin-film lithium niobate photonics platform. , 2020, Optics express.

[2]  D. Dai,et al.  Ultra-Sharp Multimode Waveguide Bends With Dual Polarizations , 2020, Journal of Lightwave Technology.

[3]  H. Tang,et al.  Toward 1% single-photon anharmonicity with periodically poled lithium niobate microring resonators , 2020, 2007.07411.

[4]  D. Dai,et al.  Polarization Coupling of $X$-Cut Thin Film Lithium Niobate Based Waveguides , 2020, IEEE Photonics Journal.

[5]  J. Xia,et al.  Fundamental mode hybridization in a thin film lithium niobate ridge waveguide. , 2019, Optics express.

[6]  H. Tang,et al.  Periodically poled thin-film lithium niobate microring resonators with a second-harmonic generation efficiency of 250,000%/W , 2019, Optica.

[7]  Chao Tang,et al.  Ultra-efficient frequency conversion in quasi-phase-matched lithium niobate microrings , 2019, Optica.

[8]  M. Lončar,et al.  Microwave-to-optical conversion using lithium niobate thin-film acoustic resonators , 2019, Optica.

[9]  M. Lončar,et al.  Phononic Band Structure Engineering for High- Q Gigahertz Surface Acoustic Wave Resonators on Lithium Niobate , 2019, Physical Review Applied.

[10]  Marko Loncar,et al.  Monolithic lithium niobate photonic circuits for Kerr frequency comb generation and modulation , 2018, Nature Communications.

[11]  Oliver King,et al.  An Integrated Low-Voltage Broadband Lithium Niobate Phase Modulator , 2019, IEEE Photonics Technology Letters.

[12]  Di Liang,et al.  Submicron-resonator-based add-drop optical filter with an ultra-large free spectral range. , 2019, Optics express.

[13]  Q. Lin,et al.  Optical Parametric Generation in a Lithium Niobate Microring with Modal Phase Matching , 2018, Physical Review Applied.

[14]  Joseph M. Kahn,et al.  Broadband electro-optic frequency comb generation in a lithium niobate microring resonator , 2018, Nature.

[15]  Alberto Peruzzo,et al.  Tunable large free spectral range microring resonators in lithium niobate on insulator , 2018, Scientific Reports.

[16]  P. Winzer,et al.  Integrated lithium niobate electro-optic modulators operating at CMOS-compatible voltages , 2018, Nature.

[17]  Bingxi Xiang,et al.  Simulation and Analysis of Single-Mode Microring Resonators in Lithium Niobate Thin Films , 2018, Crystals.

[18]  Daoxin Dai,et al.  Low-loss and low-crosstalk multimode waveguide bend on silicon. , 2018, Optics express.

[19]  Q. Lin,et al.  Dispersion-engineered high quality lithium niobate microring resonators , 2018, 2018 Conference on Lasers and Electro-Optics (CLEO).

[20]  Arnan Mitchell,et al.  Status and Potential of Lithium Niobate on Insulator (LNOI) for Photonic Integrated Circuits , 2018 .

[21]  Michal Lipson,et al.  Nanophotonic lithium niobate electro-optic modulators. , 2017, Optics express.

[22]  Marko Loncar,et al.  Monolithic ultra-high-Q lithium niobate microring resonator , 2017, 1712.04479.

[23]  G. Guo,et al.  Metasurface-assisted phase-matching-free second harmonic generation in lithium niobate waveguides , 2017, Nature Communications.

[24]  J. Xia,et al.  Grating Coupler for an On-Chip Lithium Niobate Ridge Waveguide , 2017, IEEE Photonics Journal.

[25]  F. Gao,et al.  Thermo-optic effects in on-chip lithium niobate microdisk resonators. , 2016, Optics express.

[26]  Shilei Jin,et al.  LiNbO3 Thin-Film Modulators Using Silicon Nitride Surface Ridge Waveguides , 2016, IEEE Photonics Technology Letters.

[27]  J. Bowers,et al.  Passive technologies for future large-scale photonic integrated circuits on silicon: polarization handling, light non-reciprocity and loss reduction , 2012, Light: Science & Applications.