Silicon-based lithium niobate high-speed light modulator and preparation method thereof

Abstract

The invention discloses a silicon-based lithium niobate high-speed light modulator and a preparation method thereof. The modulator comprises a silicon substrate wafer, a lower silicon dioxide cladding, lithium niobate film, an optical waveguide, a metal electrode, a silicon V-shaped groove and a coupling optical fiber, wherein the lower silicon dioxide cladding is located on the upper surface of the silicon substrate wafer, and the lithium niobate film is located on the lower silicon dioxide cladding. The silicon-based lithium niobate high-speed light modulator has the advantages that heterogeneous integration of a lithium niobate single crystal body and a silicon single crystal body is achieved; by utilizing the thin-film lithium niobate wafer and the characteristics such as low dielectric constant and low dielectric loss of the lower silicon dioxide cladding, improvement of modulation rate (or modulation bandwidth) of the lithium niobate light modulator can be achieved; by utilizingthe thin-film lithium niobate wafer and the high insulativity of the lower silicon dioxide cladding, intensity increase of microwave electromagnetic fields distributed in the lithium niobate film canbe achieved, the modulation efficiency of electric fields to light fields is improved, and the driving voltage of the modulator is reduced.

Description

Technical field [0001] The invention belongs to the technical field of optical communication, and particularly relates to a silicon-based lithium niobate high-speed optical modulator and a preparation method thereof. Background technique [0002] In recent years, with the widespread application of optical communication technology in traditional services such as broadband networks, mobile communications, financial transactions, and data centers, as well as emerging services such as cloud computing, big data, and 5G communications, traditional technologies have improved the speed, capacity, and delay of communications. It has been difficult to meet the needs of people's daily life. Therefore, communication operators are increasingly adopting coherent processing technologies in the architecture of optical networks to realize the establishment of optical transport networks with high speed, large capacity, low delay, and low energy consumption. [0003] In the coherent processing techn...

AI Technical Summary

Problems solved by technology

[0005] (1) The low electro-optical modulation efficiency of existing lithium niobate high-speed optical modulators makes the driving voltage of the device higher, especially when multiple MZ modulators are connected in parallel to construct coherent optical modulators such as PM-QPSK, the device's The driving voltage will increase significantly;

[0006] (2) The existing lithium niobate high-speed optical modulator has to increase the length of the traveling wave electrode to reduce the driving voltage of the device, but this undoubtedly increases the volume of the device;

[0007] (3) It is difficult to prepare lithium niobate crystals on semiconductor wafers such as gallium arsenide or silicon by coating technology, making it difficult to achieve heterogeneous integration or monolithic integration of lithium niobate and lasers, photodetectors and other structures

However, the high cost and temperature sensitivity of indium phosphide optical modulators, the nonlinear electro-optic effect of silicon optical modulators, and the theoretical upper limit of 60 GHz modulation bandwidth also limit the wide application of these two new optical modulator technologies.

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