A pm-qpsk integrated optical modulator based on lithium niobate and its working method

A technology of optical modulators and working methods, which is applied in the fields of instruments, optics, nonlinear optics, etc., can solve problems such as production difficulties and complex devices, and achieve good modulation effects, reduce transmission loss, and reduce power consumption.

Inactive Publication Date: 2019-01-15
SHANDONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional IQ modulator needs to achieve a phase difference of π / 2 between the upper and lower channels. There are usually two methods. One is to control the phase delay of the upper and lower channels by controlling the length difference between the upper and lower waveguides. The phase delay requires a process tolerance of about 0.3 microns, which is quite difficult to manufacture. The second is to change the refractive index of the waveguide by adding electrodes to change the optical path difference between the upper and lower channels to achieve the effect of π / 2 phase delay between the upper and lower channels. but this makes the device more complex

Method used

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  • A pm-qpsk integrated optical modulator based on lithium niobate and its working method
  • A pm-qpsk integrated optical modulator based on lithium niobate and its working method
  • A pm-qpsk integrated optical modulator based on lithium niobate and its working method

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Effect test

Embodiment 1

[0045] Such as figure 1 , Figure 5 shown.

[0046] A PM-QPSK integrated optical modulator based on lithium niobate, including an upper electrode, a lower electrode, a substrate and a lithium niobate crystal; the lithium niobate crystal is engraved with polarization demultiplexers in sequence according to the direction of the optical path, and two parallel circuits The IQ modulator and the polarization multiplexer; the upper electrode and the lower electrode are respectively arranged on the upper surface of the lithium niobate crystal and under the substrate; the polarization demultiplexer and the polarization multiplexer are respectively MZI-based lithium niobate polarization Demultiplexers and MZI-based lithium niobate polarization multiplexers.

Embodiment 2

[0048] Such as figure 2 shown.

[0049] The PM-QPSK integrated optical modulator based on lithium niobate as described in Embodiment 1, the difference is that the polarization demultiplexer includes a first MMI structure and a second MMI structure connected by two waveguide arms with different lengths, The optical path difference between the two waveguide arms is π. The lengths of the two waveguide arms are different, that is, the optical paths of the two are different, and due to the birefringence of lithium niobate, T E , T M The two polarization states have different refractive indices in the waveguide arm, and the two polarization states can be separated by adjusting the length of the waveguide arm so that the optical path difference is π.

Embodiment 3

[0051] Such as image 3 shown.

[0052] The PM-QPSK integrated optical modulator based on lithium niobate as described in Embodiment 1, the difference is that the polarization multiplexer includes a third MMI structure and a fourth MMI structure connected by two waveguide arms with different lengths, the two The optical path difference of each waveguide arm is π. The structure and basic principle of the polarization multiplexer are similar to the polarization demultiplexer, which is the reverse process of the working principle of the polarization demultiplexer. The polarization multiplexer multiplexes two channels of light with different polarization states modulated by the IQ modulator into the same beam of outgoing light. After polarization demultiplexing and polarization multiplexing, the amount of information carried by the optical carrier is doubled. The traditional polarization demultiplexer and polarization multiplexer are manufactured based on silicon-based technolog...

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Abstract

The invention relates to a lithium niobate-based PM-QPSK integrated light modulator and a working method thereof. The lithium niobate-based PM-QPSK integrated light modulator comprises an upper electrode, a lower electrode, a lining and lithium niobate crystals, wherein a polarization demultiplexer, two IQ modulators in parallel and a polarization multiplexer are sequentially etched on the lithium niobate crystals in a light path direction; the upper electrode and the lower electrode are respectively arranged on the upper surface of the lithium niobate crystals and below the lining; the polarization demultiplexer and the polarization multiplexer are respectively a lithium niobate polarization demultiplexer based on MZI and a lithium niobate polarization multiplexer based on MZI. As the lithium niobate-based PM-QPSK integrated light modulator is provided with the lithium niobate polarization demultiplexer and the lithium niobate polarization multiplexer manufactured on a birefrigent effect of lithium niobate, the conventional method that a polarization multiplexer is manufactured on the basis of a silicon substrate is changed, a polarization demultiplexer and a polarization multiplexer based on the silicon substrate and IQ modulators are integrated on the same piece of crystal, and the allowance is far smaller than a silicon substrate process.

Description

technical field [0001] The invention relates to a PM-QPSK integrated optical modulator based on lithium niobate and a working method thereof, belonging to the technical field of optical modulators. Background technique [0002] The optical modulator is a key device for high-speed, short-distance optical communication and one of the most important integrated optical devices. There are four types of external modulators in general optical fiber communication systems: acousto-optic (AO) modulators, magneto-optic modulators, electro-optic (EO) modulators and electro-absorption (EA) modulators. Among them, the electro-optic modulator, which depends on the change of the light-carrying mode of a certain planar waveguide, is one of the two main types of modulators used in modern optical fiber systems. [0003] Lithium niobate thin film materials have excellent physical properties such as electro-optic, nonlinear optics, and acousto-optic, and have potential advantages for optoelectr...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G02F1/03
CPCG02F1/0305G02F1/0311G02F1/0316
Inventor 季伟尹锐王军宝公姿苏
Owner SHANDONG UNIV
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