Optical fiber electro-optic intensity modulator and preparation method thereof

Abstract

The invention provides an optical electro-optic intensity modulator and a preparation method thereof. The optical electro-optic intensity modulator comprises first optical fibers (1) and second optical fibers (2). A luminous power coupled zone (3) is formed by heating, axially stretching, cladding and mixing the first optical fibers (1) and the second optical fibers (2). A pair of electrodes (4) are symmetrically arranged on two sides of the luminous power coupled zone (3). Electrode leads (10) are connected on the electrodes. High voltage is applied to the pair of electrodes (4). Polarization treatment is conducted on the luminous power coupled zone (3), so that optical fiber cladding (8) between two fiber cores (7) in the luminous power coupled zone (3) has an electro-optic modulation property. According to the optical electro-optic intensity modulator, the relationship between coupling efficiency and refractive indexes is utilized, changes in modulation voltage is directly converted into changes in the intensity of output light, and the optical electro-optic intensity modulator has the advantages that a polarized area is shortened to the magnitude of centimeters, the size is small, the modulation speed is high, and integration is realized conveniently.

Description

technical field [0001] The invention relates to an optical fiber electro-optic intensity modulator. Background technique [0002] Electro-optical modulation device is a kind of modulation device widely used in high-speed optical communication and other fields at present. The commonly used LiNbO 3 Although the phase modulator has the advantages of large bandwidth and high speed, it also has disadvantages such as very difficult coupling with the optical fiber, low coupling efficiency, high coupling cost, and expensive manufacturing. With the continuous improvement of people's requirements for communication performance, the demand for all-fiber devices to replace traditional modulation devices has become more and more urgent. The optical fiber has the advantages of low loss, wide frequency bandwidth, high speed, no interference, small size, light weight, etc. Therefore, the application of optical fiber to electro-optic modulation devices has become a development trend in the f...

AI Technical Summary

Problems solved by technology

And the thermally polarized single-mode fiber is used as an electro-optic phase modulator to make a single-mode fiber Mach-Zehnder interferometer, and a single-mode fiber electro-optic intensity modulator with a wavelength of 0.83 μm at a modulation frequency of 150KHz is demonstrated. Made of single-mode optical fiber, the polarization state of light changes greatly during optical transmission. In the experiment, a polarization controller is required to control the polarization state in the Mach-Zehnder interferometer system, and Kazansky's polarized optical fiber electrode is pressed on the optical fiber. , there is no practical packaging of electrodes, so there are difficulties in polarization state control and electrode packaging. This structure cannot be applied to the polarization of longer optical fibers, and it cannot be used for high-speed and long-term electro-optic modulation.

[0004] In 2000, Chen Zhe of Jinan University used thermally polarized 1.3μm optical wavelength Panda PM fiber to make a fully polarization-maintaining fiber electro-optic phase modulator with microstrip electrodes (thermally polarized fiber optic device coated with microstrip electrodes, patent application No.: 00113687.9), the phase modulator solves the problems of polarization state control and electrode packaging, but the phase change is caused by the change of the refractive index of the modulator, and then converted into a change of light intensity by using the interferometer structure, and the extremely The refractive index change caused by the chemical fiber is very small. In order to achieve the modulation effect, the length of the device can only be lengthened, which brings the influence of capacitance and inductance to the modulator, and affects the modulation speed at the same time.

However, the electro-optical coefficient generated by polarization is very small, and the length of the device needs to be lengthened to achieve phase modulation, which will bring about the influence of capacitance and inductance, and affect the modulation speed at the same time; in order to achieve intensity modulation, an interferometer structure is required, which brings many problems to the system. inconvenient

[0006] From the perspective of the characteristics of the polarized fiber itself, since the electro-optical coefficient generated by the polarized fiber core is very small, a long fiber length (usually more than 10cm) is required to obtain the ideal modulation effect, and the usual polarized fiber devices are It is a phase modulation device, and it needs to be built into an interferometer structure to realize the intensity modulation function, which brings a lot of inconvenience to both the production and practical application of this type of device

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