A tunable narrow linewidth photogenerated microwave source based on polarization control

Abstract

The invention discloses an adjustable narrow linewidth photogenerated microwave source based on polarization control, which comprises a high reflectivity fiber grating, a high gain fiber, a low reflectivity polarization maintaining fiber grating, a stress adjusting device, a single-mode semiconductor pumped laser, an optical wavelength division multiplexer, a polarization beam splitter, a polarization controller, an optical coupler and a photodetector. The invention discloses an adjustable narrow linewidth photogenerated microwave source based on polarization control, which controls the birefringence distribution in the low reflectivity polarization maintaining fiber grating by adjusting the stress magnitude of the low reflectivity polarization fiber grating by a stress adjusting device, thereby controlling the laser frequency working in different polarization modes in a resonant cavity. Finally, a tunable narrow linewidth microwave source is generated by beat-frequency technique usinga dual-wavelength narrow linewidth laser with variable frequency intervals.

Description

Technical field [0001] The present invention mainly uses microwave photonics technology, relates to a communication system that uses optical technology to process radio frequency signals, and specifically relates to an adjustable narrow linewidth photo-generated microwave source based on polarization control. Background technique [0002] Photo-generated microwave technology is an optical technology that carries microwave and millimeter wave signals in optical signals and realizes the transmission of radio frequency signals in optical transmission media such as optical fibers. In optical radio frequency systems, the generation of radio frequency signals is realized by regulating the laser signal. , Conversion and modulation. Optical microwave technology uses the advantages of low optical signal transmission loss, long transmission distance, and anti-interference in optical fiber communication, and overcomes the shortcomings of low frequency upper limit and large signal noise of t...

AI Technical Summary

Problems solved by technology

The optical heterodyne method generates microwave signals by beat frequency, which has a simple structure and low cost, but it is difficult to achieve an adjustable output frequency

External modulation is to modulate the optical signal through the phase modulator, which can generate a microwave signal with twice the frequency or even higher than the modulation signal, so it is easy to obtain high-frequency microwave signals, but the disadvantage of this method is the price of the phase modulator Expensive and additional modulation signal generator, and the insertion loss of the modulator itself is large, and the optical power it can withstand is limited; the photoelectric oscillator generates microwave signals through the stable oscillation generated by the photoelectric loop, and its frequency can be adjusted in a large range. The microwave signal quality is high, but the structure is relatively complex, and there are high requirements for some components such as tunable filters

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