Grating coupler on single-crystal lithium niobate thin film

Chen, Zhihua; Wang, Yiwen; Jiang, Yunpeng; Kong, Ruirui; Hu, Hui

doi:10.1016/j.optmat.2017.05.061

Cited by 29 publications

(13 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The measured coupling loss per coupler was ≈12 dB, which is a significant fabrication penalty compared to the simulated coupling loss of ≈4 dB and shows that the fabrication of the grating couplers needs further optimization. Furthermore, the design of the grating coupler itself can be improved, by adding a bottom reflective layer to increase the coupling efficiency …”

Section: Photonic Building Blocks In Lnoimentioning

confidence: 99%

“…Furthermore, the design of the grating coupler itself can be improved, by adding a bottom reflective layer to increase the coupling efficiency. [61] The potential grating coupler efficiency improvements that are possible can be seen when comparing these results with grating couplers fabricated in the optical waveguide platform of SiN, which has a similar refractive index compared to lithium niobate, where coupling efficiencies of 4-5 dB per coupler are achievable. [62][63][64] The limited spectra bandwidth and multi dB insertion loss penalty make grating couplers unsuitable for applications where optical power on chip is a priority such as nonlinear optics.…”

Section: Optical Interfacesmentioning

confidence: 99%

See 1 more Smart Citation

Status and Potential of Lithium Niobate on Insulator (LNOI) for Photonic Integrated Circuits

Boes

Corcoran

Chang

et al. 2018

Laser & Photonics Reviews

542

290

View full text Add to dashboard Cite

Lithium niobate on insulator (LNOI) technology is revolutionizing the lithium niobate industry, enabling higher performance, lower cost and entirely new devices and applications. The availability of LNOI wafers has sparked significant interest in the platform for integrated optical applications, as LNOI offers the attractive material properties of lithium niobate, while also offering the stronger optical confinement and a high optical element integration density that has driven the success of more mature silicon and silicon nitride (SiN) photonics platforms. Due to some similarities between LNOI and SiN, established techniques and standards can readily be adapted to the LNOI platform including a significant array of interface approaches, device designs and also heterogeneous integration techniques for laser sources and photodetectors. In this contribution, we review the latest developments in this platform, examine where further development is necessary to achieve more functionalities in LNOI integrated optical circuits and make a few suggestions of interesting applications that could be realized in this platform.

show abstract

Section: Photonic Building Blocks In Lnoimentioning

confidence: 99%

Section: Optical Interfacesmentioning

confidence: 99%

Status and Potential of Lithium Niobate on Insulator (LNOI) for Photonic Integrated Circuits

Boes

Corcoran

Chang

et al. 2018

Laser & Photonics Reviews

542

290

View full text Add to dashboard Cite

show abstract

“…By performing Fourier transforms, such as the Poynting vector, normalized transmission, and far field projections could be obtained. PML boundaries could absorb electromagnetic energy incident upon them, allowing radiation to propagate out of the computational area without interfering with the field inside [19]. The total ring loss was due to the bend loss and other scattering losses at the coupling region.…”

Section: Device Descriptionmentioning

confidence: 99%

Simulation and Analysis of Single-Mode Microring Resonators in Lithium Niobate Thin Films

2018

View full text Add to dashboard Cite

The single-mode microring resonators on lithium niobate thin films were designed and simulated using 2.5-D variational finite difference time domain mode simulations from Lumerical mode Solutions. The single-mode conditions and the propagation losses of lithium niobate planar waveguide with different SiO2 cladding layer thicknesses were studied and compared systematically. The optimization of design parameters such as radii of microrings and gap sizes between channel and ring waveguides were determined. The key issues affecting the resonator design such as free spectral range and Quality Factor were discussed. The microring resonators had radius R = 20 μm, and their transmission spectrum had been tuned using the electro-optical effect.

show abstract

“…Benefited from the large refractive index contrast between the LN and the silicon oxide, as well as the robust dry-etching technology of LN, ridge waveguides fabricated on thin-film LN present a tight light confinement, and a small bending radius can also be expected. High-performance and highly-integrated electro-optic modulators [9], [14], [15], micro-ring resonators [16]- [18], grating couplers [19], and photonic crystal devices [20], [21] fabricated on the thin film LN have been demonstrated on this LNOI platform.…”

Section: Introductionmentioning

confidence: 99%

Polarization Coupling of $X$-Cut Thin Film Lithium Niobate Based Waveguides

et al. 2020

View full text Add to dashboard Cite

Thin film lithium niobate (LN) shows great potentials for highly compact passive and active devices. As LN is an anisotropic material, waveguides made on it exhibit different mode properties from those on conventional isotropic materials. We study the effective refractive indices of fundamental modes of two polarizations in etched ridge waveguides on an X-cut LN thin film. Mode hybridization phenomenon, where the effective refractive indices of the two polarizations are close, is analyzed in detail with different structural parameters. Transmission through a 90°bend, which is a typical routing element for a photonic chip, is simulated. Significant polarization coupling related to the mode evaluation through the bend is observed, and becomes the dominant fact limiting the performance of this element. In order to ensure a low bending loss, the required bending radius is much larger than that for waveguides on an in-plane isotropic material, e.g. a Z-cut LN thin film. Mode hybridization also plays an important role in the performance of the 90°bend, which should be avoided. Generally, decreasing the thickness of the LN thin film, working at a longer wavelength, or confining the propagation angle on a chip would help to decrease the polarization coupling.

show abstract

Grating coupler on single-crystal lithium niobate thin film

Cited by 29 publications

References 17 publications

Status and Potential of Lithium Niobate on Insulator (LNOI) for Photonic Integrated Circuits

Status and Potential of Lithium Niobate on Insulator (LNOI) for Photonic Integrated Circuits

Simulation and Analysis of Single-Mode Microring Resonators in Lithium Niobate Thin Films

Polarization Coupling of $X$-Cut Thin Film Lithium Niobate Based Waveguides

Contact Info

Product

Resources

About