Microwave photonic filter based on photonic crystal fiber sagnac loop

Abstract

A microwave photonic filter based on a photonic crystal fiber sagnac loop comprises a broadband light source, a sagnac loop, a coupler B, a spectrum analyzer, a phase modulator, an analog signal generator, a single mode fiber, a photoelectric detector and a spectrum analyzer. The sagnac loop is composed of an sdB coupler A, a polarization controller and a liquid-filled photonic crystal fiber; the photonic crystal fiber of the sagnac loop is filled with liquid, the birefringence is changed by changing the temperature, the wavelength interval of the sagnac loop transmission spectrum is affected, the wavelength interval of input light is changed accordingly, and the filter passband center frequency can be tuned continuously. The microwave photonic filter has the advantages that the microwave photonic filter is simple in structure and easy to implement, the photonic crystal fiber of the sagnac loop is filled with liquid, the temperature is changed, the continuous tuning of the filter passband center frequency can be implemented, the dynamic response range is large, the manufacture technology is mature, cost is low, and the promotion and application are benefited.

Description

Technical field [0001] The invention belongs to the technical field of microwave photon filtering, in particular to a microwave photon filter based on a photonic crystal fiber Sagnac ring. Background technique [0002] Microwave photonic filter is an important branch of microwave photonics. It modulates the input radio frequency (RF) signal to an optical signal through a modulator, processes the RF signal in the optical domain, and finally outputs the filtered microwave through an optical receiver signal. Using this method has the advantages of low loss, high bandwidth, immunity to electromagnetic interference, light weight, and support for high sampling frequencies. These significant advantages make the microwave photon filter system a hot technology in broadband radio frequency signal processing and attract international attention. In recent years, researchers have conducted in-depth research on it and have obtained many experimental results, such as: tunable microwave photon ...

AI Technical Summary

Problems solved by technology

The tunability of microwave photonic filters is very important, and it is also a research hotspot in this field, but there is a problem that the tuning range is small and cannot be continuously adjusted

The common method is to use tunable delay lines, tunable modulators and other devices, but these methods generally need to be equipped with high-cost tunable light sources, and there are still some difficulties in application.

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