Adjustable-bandwidth filter based on silicon-based waveguide optical grating

Abstract

The invention discloses an adjustable-bandwidth filter based on a silicon-based waveguide optical grating. The filter comprises a two-stage optical grating filter. A left downloading end of the first-stage optical grating filter is connected with an input single-mode waveguide of the second-stage optical grating filter. A right direct-connection end of the second-stage optical grating filter is connected with the lower port of a right asymmetric gradual-change directional coupler of the first-stage optical grating filter, thereby achieving the signal recycling. The cascading of the filter is employed for adjusting the range of an overlapping range of two-stage optical grating spectral lines through a thermode, thereby forming the filter. The filter employs the asymmetric gradual-change directional coupler, so the filter is large in tolerance and is small in insertion loss. Based on the optical grating filters, the bandwidth adjustment range is not limited by FSR. The asymmetric gradual-change directional coupler is used for enabling a signal of the direct-through end of the second optical grating filter to be uploaded and synthesized in a no-loss manner, thereby achieving no bandwidth loss. The filter is manufactured through the technology of planar integrated optical waveguides, is formed through one-time etching, is low in cost, is high in performance, and is small in loss.

Description

technical field [0001] The invention relates to a silicon-based waveguide grating filter, in particular to a bandwidth-tunable filter based on a silicon-based waveguide grating. Background technique [0002] Since the 21st century, the development of silicon-based integrated optoelectronic devices has become an important research direction for the development of integrated optical devices, and various new optical devices based on silicon-based waveguides have been reported continuously. Since silicon-based optical devices can be combined with the existing very mature CMOS process, there is a wealth of process technology accumulation, low production cost, high reliability, easy for mass production, and can be combined with the circuit system to form a multifunctional optoelectronic Hybrid modules and systems are widely used in many fields such as communication, sensing, military, and biology, and these put forward higher requirements for optical communication, such as multi-s...

AI Technical Summary

Problems solved by technology

[0003] Scholars have conducted a series of explorations on silicon-based bandwidth-tunable filters based on the advantages of silicon materials, such as large refractive index difference, low loss, and CMOS compatibility. The bandwidth-tunable filters based on microrings and Mach-Zehnder interferometers Due to the limitation of its own FSR, it is difficult to realize a wide range of bandwidth adjustable, and it cannot cover all the C-band, and the multi-stage micro-ring adjustment is troublesome, while the grating bandwidth adjustable filter can be used due to its large bandwidth range and no Affected by FSR, a wide range of bandwidth can be adjusted

However, at present, silicon-based grating-based filters realize the transmission structure of reflected signals, such as MMI, Y bifurcation, etc., which are relatively complicated, have small tolerances, and have a certain insertion loss, so the realization of non-destructive, large-tolerance transmission type gratings Filter bandwidth adjustable filter has great significance

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