Optimizing two-dimensional polarization-diversity metagrating couplers for silicon photonics

Tu，Xin1; Wu，Yiheng1; Huang，Tianye1; Zhang，Jing1; Ping，Perry Shum2

2022-04-01

10.1364/JOSAB.453289

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS   影响因子和分区

0740-3224

1520-8540

Polarization-diversity couplers are promising industrially scalable optical devices that can couple optical signals with unknown polarization states into silicon photonic chips. Here we propose a novel, to the best of our knowledge, two-dimensional (2D) metagrating coupler (MGC) for the polarization-diversity system, which improves its coupling efficiency for both polarizations. Compared with the previously reported 2D grating couplers (GCs) with identical grating cells, the proposed apodized design gradually changes the aspect ratio and orientation angles of the elliptical patterns simultaneously. This 2D array of the varied grating cells modulates the diffracted mode field patterns and phases locally, and achieves a better overlap with the Gaussian fiber modes for both polarizations. The peak coupling loss (PCL) for the S-polarized and P-polarized light are −1.6 dB and −2.7 dB, respectively. The calculated polarization dependent loss is lower than 0.2 dB from 1522 nm to 1540 nm. The device is robust to the fabrication tolerance and fiber misalignment. The simulated fabrication tolerance analysis show that the etch depth error of ±20 nm results in less than 0.3 dB and 0.1 dB PCL drop, while the grating cell feature size error of ±40 nm results in less than 0.6 dB and 0.2 dB PCL drop for both types of polarization light, respectively. The fiber misalignment should be within the range from −2 µm to +2 µm in two perpendicular directions, and the coupling angle deviation should be within the range from −3 to +3, in order to assure 0.5 dB penalty loss for both polarizations. The performance of the design is insensitive to the mask misalignments. To assure 0.5 dB penalty loss for both polarizations, 1θ is suggested to be within the range from −3 to +3

SCI ; EI

英语

其他

Fundamental Research Funds for the Central Universities[162301132703];Wuhan Municipal Science and Technology Bureau[2018010401011297];National Natural Science Foundation of China[61605179];National Natural Science Foundation of China[61905224];Fundamental Research Funds for the Central Universities[CUG2018JM16];Fundamental Research Funds for the Central Universities[G1323511794];Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center[SJ-201816];

Optics

Optics

WOS:000778793500041

Optica Publishing Group

20221411921352

Alignment ; Aspect ratio ; Fits and tolerances ; Light polarization ; Photonic devices ; Silicon photonics

Mechanical Devices:601.1 ; Light/Optics:741.1 ; Optical Devices and Systems:741.3

PHYSICS

2-s2.0-85127546233

Scopus

1.School of Mechanical Engineering and Electronic Information,China University of Geosciences,Wuhan,No. 388 Lumo Road,430074,China
2.The Department of Electrical and Electronic Engineering,Southern University of Science and Technology,Shenzhen,China

Tu，Xin,Wu，Yiheng,Huang，Tianye,et al. Optimizing two-dimensional polarization-diversity metagrating couplers for silicon photonics[J]. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS,2022,39(4):1256-1262.

Tu，Xin,Wu，Yiheng,Huang，Tianye,Zhang，Jing,&Ping，Perry Shum.(2022).Optimizing two-dimensional polarization-diversity metagrating couplers for silicon photonics.JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS,39(4),1256-1262.

Tu，Xin,et al."Optimizing two-dimensional polarization-diversity metagrating couplers for silicon photonics".JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 39.4(2022):1256-1262.