Method and devices for optically generating high-frequency microwave signals

Abstract

The invention relates to a method and devices for optically generating high-frequency microwave signals. The method comprises the following steps of: respectively carving Fiber Bragg Grating with matched wavelength and same period at the two end parts of high-gain polarization-maintaining optical fiber, generating dual-wavelength laser in orthogonality with polarization state by utilizing different index of refraction of the core layer of the high-gain polarization-maintaining optical fiber along the directions of a fast axis and a slow axis, and leading the dual-wavelength laser to have the same polarization state after passing through a polarizer by adjusting a polarization controller, thus obtaining the high-frequency microwave signals. The devices for realizing the method comprise a laser pumping source with the wavelength of 980nm, a 980nm / 1550nm optical wavelength-division multiplex, the polarization controller, the polarizer, a photodetector and the high-gain polarization-maintaining optical fiber; and the two end parts of the high-gain polarization-maintaining optical fiber are respectively carved with Fiber Bragg Grating with matched wavelength and same period. The invention can generate microwave signals with high quality and high frequency, has the advantages of simple structure, easy realization, low cost and the like, and is applicable for the fields of research and application such as microwave communication, ROF and the like.

Description

technical field [0001] The invention belongs to the technical field of microwave photonics, and relates to a dual-wavelength single longitudinal mode distributed Bragg reflection (DBR) fiber laser based on a high-gain polarization-maintaining fiber and a method for generating high-frequency microwave signals realized by using the laser, and realizing the method The means of the method. Background technique [0002] At present, the operating frequencies of most wireless communication systems are concentrated below 5GHz, but with the rapid growth of the amount of information in human society, the existing communication frequencies are becoming more and more congested, so it will become inevitable to develop higher frequency communication bands. Traditional microwave signal generation and processing are based on electrical methods. However, due to the limitation of electronic bottlenecks, with the increase of microwave signal frequency, its generation and processing are facing ...

AI Technical Summary

Problems solved by technology

[0003] Dual-wavelength single-longitudinal-mode lasers are an important method for optically generating microwave signals, but most of the existing dual-wavelength single-longitudinal-mode lasers are based on specially designed fiber gratings with extremely narrow transmission bands (less than 1pm). Such fiber gratings are not only complicated to design and manufacture, but generally can only be used to generate microwave signals below 40 GHz, and it is very difficult to generate microwave signals higher than 40 GHz

In addition, because the cavity length of such a fiber laser is generally long, it is easily disturbed by the external environment and the generated microwave signal is not stable enough.

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