Novel Optical Fiber Online Modulator Based on Lithium Niobate Thin Film

Abstract

The invention discloses a novel optical fiber online modulator based on lithium niobate thin film. Aiming at the problems of large insertion loss and poor stability existing in the existing electro-optic modulator, the modulator of the invention includes a transmission optical fiber, and the transmission optical fiber is divided into The three parts are recorded as the first part, the second part, and the third part in turn; the first part is the input fiber, the second part is the modulation area, and the third part is the output fiber; part of the cladding is removed from the transmission fiber in the modulation area, and Fabricate thin-film lithium niobate waveguides and tuning electrodes on the plane where part of the cladding is removed; using the electro-optical effect of lithium niobate, according to the phase change of the optical field propagating in the thin-film lithium niobate waveguide, or the change of the overall mode field distribution of the device, The modulation of the intensity of the final output optical signal is realized, and the online modulator of the present invention has the advantages of small device volume and stable performance.

Description

technical field [0001] The invention belongs to the field of optical communication, and in particular relates to the structure and function realization of a novel optical fiber online modulator based on lithium niobate thin film. Background technique [0002] In the era of information explosion, big data, Internet of Things, artificial intelligence and other technologies gradually penetrate into people's lives, and the diversity and complexity of information services make the transmission speed and capacity of communication systems more and more demanding. Optical fiber communication is far superior to cable and microwave communication due to its transmission frequency bandwidth, high anti-interference and low signal attenuation, and has become the main transmission mode in world communication. Optical fiber communication system mainly consists of two parts: transmission and switching. Due to the advantages of low transmission loss, strong anti-electromagnetic interference ...

AI Technical Summary

Problems solved by technology

In 2014, Eun Jung Lee et al. from Asia University in South Korea reported on Nature Communications a graphene field effect transistor electroabsorption modulator using liquid ion plasma fabricated on a D-type optical fiber platform, which can achieve an insertion loss of 0.8dB , 90% modulation depth, and working voltage less than 5V, but its experimentally measured modulation bandwidth is only 30.9MHz

Although there have been some work reports on planar optical waveguide lithium niobate thin film electro-optic modulators, these modulators have a large fiber-lithium niobate thin film waveguide end face coupling loss in application, which is not conducive to device application

[0005] The electro-optic modulators that have been reported so far mainly have three limitations: First, the traditional planar optical waveguide electro-optic modulator based on lithium niobate wafer has a large size, which is not conducive to the monolithic integration of multiple devices, and the insertion loss is too large secondly, the currently proposed lithium niobate thin-film electro-optic modulator has a large coupling loss between the fiber and the waveguide, resulting in excessive insertion loss of the device, which is not conducive to application; finally, the currently proposed electro-absorption modulator based on graphene The fiber optic modulator has problems such as small bandwidth and poor stability, which cannot meet the application requirements of the actual system.

Images