https://doi.org/10.1140/epjd/s10053-022-00432-4
Regular Article - Optical Phenomena and Photonics
High-performance germanium long-wave infrared binary blazed grating coupler
1
Key Laboratory of Adaptive Optics, Chinese Academy of Sciences, 610209, Chengdu, Sichuan, China
2
Institute of Optics and Electronics, Chinese Academy of Sciences, 610209, Chengdu, Sichuan, China
3
School of Optoelectronics, University of Chinese Academy of Sciences, 100049, Beijing, China
Received:
8
November
2021
Accepted:
6
June
2022
Published online:
5
July
2022
The high-performance germanium long-wave infrared binary blazed grating coupler with perfectly vertical coupling is proposed. By the appropriate choice of grating parameters to optimize the coupling efficiency, a relatively high coupling efficiency was obtained. Moreover, by using an asymmetric subgrating structure in which a period consists of three subgratings with identical etching height and different widths, perfectly vertical fiber coupling is achieved. For perfectly vertical coupler with transverse electric polarized incident light, the coupling efficiency is 56% at the wavelength of 8 μm with a 3 dB bandwidth of 95 nm. The coupling efficiency can reach up to 76% if metal reflector is added.
Junwei Li is a postgraduate student and subordinate to the University of Chinese Academy of Sciences.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2022
