High-performance polarizer based on sub-wavelength grating structure

Abstract

The invention discloses a high-performance polarizer based on a sub-wavelength grating structure. The high-performance polarizer comprises a single-mode input waveguide, a gradual change input structure, a middle vertical sub-wavelength grating structure, an upper transverse sub-wavelength grating structure, a lower transverse sub-wavelength grating structure, a gradual change output structure and a single-mode output waveguide, the output end of the single-mode input waveguide is connected with the input end of the gradual change input structure; the output end of the gradient input structure is connected with the input end of the middle vertical sub-wavelength grating structure; the upper transverse sub-wavelength grating structure and the lower transverse sub-wavelength grating structure are located on the upper side and the lower side of the middle vertical sub-wavelength grating structure respectively. The output end of the middle vertical sub-wavelength grating structure is connected with the input end of the gradient output structure; and the output end of the gradient output structure is connected with the input end of the single-mode output waveguide. According to the invention, high-performance polarization of the TE fundamental mode can be realized in an ultra-large bandwidth range, so that the TE fundamental mode polarization device has important practical application value in the fields of optical communication, optical sensing, spectroscopy and the like.

Description

technical field [0001] The invention relates to the field of integrated optoelectronic devices, in particular to a high-performance polarizer based on a subwavelength grating structure. Background technique [0002] With the continuous development of many applications such as 5G and cloud computing, the current optical communication bandwidth has gradually become difficult to meet the demand, and the expansion of optical communication bandwidth is imminent. Among various methods of expanding bandwidth, the most promising method is to expand the optical communication band used, rather than being limited to the traditional C-band (1530-1565 nm). At present, many enterprises and companies, including China Mobile, China Telecom, Huawei, Fiberhome Communications, etc., are working hard in this direction. In the case of expanding the optical communication band, the original optical communication devices that are only suitable for the C-band will no longer be suitable, and new dev...

AI Technical Summary

Problems solved by technology

In the past ten years of research, researchers have proposed a variety of polarizer structures, including directional couplers, grating reflectors, etc., but their performance is still limited, mainly due to the limited operating bandwidth (difficult to cover all optical communication band), the loss is too large (greater than 1 dB), the polarization extinction ratio is not high enough (high extinction ratio can only be achieved in a small range), and the covering layer material is mostly air (the choice of covering layer is limited)

Images