Microwave signal source with narrow line width and high signal-to-noise ratio

Abstract

The invention belongs to the field of photoelectron and microwave photonics, and discloses a microwave signal source with a narrow line width and a high signal-to-noise ratio, for solving the problems of wide line width and high noise existing in the prior art. Pump light enters a first four-port coupler through a polarization controller and a first circulator, and a part of the pump light enters a common single-mode fiber to excite reversely transmitted first-order Stokes light; the other part of the pump light enters a light reflection mirror composed of a second circulator and a polarization-maintaining Er-doped fiber through the first four-port coupler and a micro-ring structure composed of a second four-port coupler, returns to the micro-ring structure through the light reflection mirror and enters a Brillouin gain cavity composed of the first four-port coupler and the common single-mode fiber; a part of returned pump light enters the common single-mode fiber to excite reversely transmitted next-order Stokes light, and the other part enters the first circulator and then enters a coupler; and a part of signal light passing through the coupler enters a spectrum analyzer, and the other part enters a photoelectric detector for photoelectric conversion and then enters a frequency spectrum analyzer.

Description

technical field [0001] The invention belongs to the field of optoelectronics and microwave photonics, relates to a microwave signal source with narrow line width and high signal-to-noise ratio, and is applied in the field of wireless communication. Background technique [0002] With the rapid development of mobile communications, the existing wireless spectrum resources can no longer meet the increasing business needs. In order to solve the problem of the shortage of wireless spectrum resources, Radio over Fiber (ROF) has been proposed. Wireless communication over light is a technology that combines light and microwave / millimeter waves. Microwave signals are considered to affect ROF systems because of their low phase noise, ultra-narrow linewidth, high stability, and anti-electromagnetic interference. One of the key technologies of performance. At present, the methods for generating microwaves mainly include the use of fiber Bragg grating pairs, chirped fiber Brig gratings,...

AI Technical Summary

Problems solved by technology

[0007] In order to solve the problems of wide line width, high noise, complex system and high cost in the microwave signal source based on Brillouin laser in the prior art, the present invention proposes a narrow line based on Brillouin frequency shift interval single-frequency fiber laser Microwave signal source with wide bandwidth and high signal-to-noise ratio

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