Microwave photon filter based on multi-wavelength fiber laser and chirp Bragg gratings

Abstract

The invention discloses a microwave photon filter based on a multi-wavelength fiber laser and chirp Bragg gratings, belongs to the field of microwave photon filters and particularly relates to a microwave photon filter for free spectral range multiplying. In the fiber laser, a Sagnac ring optical filter composed of a polarization maintaining optical fiber, a polarization controller and a coupler has a wavelength selection function and an apodizing function, and stable multi-wavelength output with the basically-same power is obtained by selecting a proper frequency stabilizing device. A fiber Bragg grating array serves as a time delay unit, the reflection wavelengths of the gratings correspond to the output wavelengths of a multi-wavelength laser respectively, the center distances between the adjacent gratings are the same, and thus the time delay differences generated between taps are the same. The chirp Bragg gratings are introduced so that the time delay differences between the taps are reduced, under the condition that the suppression ratio of a main lobe and a side lobe is kept unchanged, the radio frequency response for free spectral range multiplying is obtained, and the free spectral range is greatly enlarged.

Description

technical field [0001] The invention belongs to the field of microwave photon filters, in particular to microwave photon filters with multiplied free spectrum range. Background technique [0002] As an emerging discipline, microwave photonics has established a bridge between optical signal processing and microwave engineering. Compared with traditional electronic methods, microwave photonics has significant advantages in low loss, anti-electromagnetic interference, broadband processing, reconfigurability and tunability, etc. It has broken through the bottleneck of electronic equipment and attracted more and more researchers in recent years. scholars' attention. Optical microwave signal processing, optically generated microwaves, optically controlled phased array antennas, and wireless over optical are different applications of microwave photonics. Microwave photonic filters have significant applications in radio astronomy and radar systems due to their unique properties. ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is mainly to solve the problem that the existing microwave photon filter has a small free spectrum range, and proposes a microwave photon filter based on a multi-wavelength fiber laser and a chirped Bragg grating. The output of the wavelength laser is used as the light source, which reduces the complexity of the system. The output light source is apodized by using a spectral shaper, which changes the tap coefficient of the light source.

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