Open AccessUltra-compact dual-mode mode-size converter for silicon photonic few-mode fiber interfaces
Author(s) -
Lirong Cheng,
Simei Mao,
Zhenmin Chen,
Yinghui Wang,
Caiyue Zhao,
H. Y. Fu
Publication year - 2021
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.438839
Subject(s) - materials science , optics , waveguide , single mode optical fiber , silicon on insulator , mode volume , radiation mode , optoelectronics , insertion loss , photonic integrated circuit , photonic crystal fiber , photonics , optical fiber , fiber bragg grating , fiber , plastic optical fiber , multi mode optical fiber , silicon , physics , composite material
Fiber couplers usually take a lot of space on photonic integrated circuits due to the large mode-size mismatch between the waveguide and fiber, especially when a fiber with larger core is utilized, such as a few-mode fiber. We demonstrate experimentally that such challenge can be overcome by an ultra-compact mode-size converter with a footprint of only 10 µm. Our device expands TE 0 and TE 1 waveguide modes simultaneously from a 1-µm wide strip waveguide to an 18-µm wide slab on a 220-nm thick silicon-on-insulator, with calculated losses of 0.75 dB and 0.68 dB, respectively. The fabricated device has a measured insertion loss of 1.02 dB for TE 0 mode and 1.59 dB for TE 1 mode. By connecting the ultra-compact converter with diffraction grating couplers, higher-order modes in a few-mode fiber can be generated with a compact footprint on-chip.