An ultra-compact silicon-based waveguide crossover structure based on a parabolic MMI

Abstract

The invention discloses an ultra-compact silicon-based waveguide intersection structure based on a parabolic MMI, which is composed of two waveguides with the same shape but vertically intersecting, wherein the transverse branch waveguide (H) consists of a transverse branch input waveguide, a parabolic transverse branch The MMI is composed of a horizontal branch output waveguide, and the vertical branch waveguide (V) is composed of a vertical branch input waveguide, a parabolic vertical branch MMI and a vertical branch output waveguide. The characteristic of this structure is that both the parabolic horizontal branch MMI and the parabolic vertical branch MMI adopt the same parabolic MMI structure with wide ends and a narrow middle. Compared with the existing MMI waveguide cross structure, the structure of the present invention maintains the advantages of low loss and low crosstalk of the MMI waveguide cross structure, and at the same time, because the MMI has a parabolic structure, the structure of the present invention has a more compact size, The fabrication of larger scale integrated optical circuits can be realized.

Description

technical field [0001] The invention relates to an ultra-compact silicon-based waveguide cross structure based on a parabolic MMI, belonging to the fields of integrated optics, microelectronics and optoelectronics. Background technique [0002] With the development of microelectronics technology, the problems caused by signal interconnection on microelectronic chips have become increasingly prominent, and the "electronic bottleneck" has become a problem that limits the continuous improvement of the performance of microelectronic chips. The introduction of optical interconnection technology has become a solution to this problem. Effective Ways. [0003] Since Dr. Miller of Bell Laboratories in the United States proposed the concept of "integrated optics" in 1969, the theory and technology of integrated optics have developed rapidly. After fifty years of research and development by researchers, some integrated optical devices, such as optical splitters, optical switches, and ...

AI Technical Summary

Problems solved by technology

It was reported in 2010 (Ding, Tang et al.2010) that the impedance matching metamaterial was applied to the crossing position of the waveguide. The test results showed that the loss was 0.04dB and the crosstalk was -40dB. The disadvantage is that the metamaterial is expensive and difficult to mass produce.

figure 2 (a) is a waveguide intersection structure based on elliptical MMI. According to literature reports (Le, Xu et al.2017), this structure can reduce the loss of waveguide intersection to 0.15dB, and the crosstalk is lower than -46dB; (b ) is a waveguide intersection structure based on an ellipse-two-step etching MMI (the light-colored oblique area is a shallow etching area) (Bogaerts, Dumon et al.2007), and the transverse refractive index can be reduced by using a two-step etching process Poor, which is beneficial to reduce loss and crosstalk, but the process is more complicated; (c) is a waveguide cross structure based on tapered waveguide cascaded MMI, which is usually formed by cascading multiple Gaussian tapered waveguides. It is more complicated (Chen 2012); (d) is a waveguide intersection structure based on the side SWG type MMI. The introduction of the subwavelength grating (SWG) structure is beneficial to increase the working bandwidth (Zhang, Hosseini et al. The reduced refractive index difference is also beneficial to reduce loss and crosstalk, but it has higher requirements on the process

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