Broadband linear frequency modulation narrow linewidth fiber laser and implementation method thereof

Abstract

The invention discloses a broadband linear frequency modulation narrow linewidth fiber laser and an implementation method thereof. The implementation method comprises the steps that: a narrow linewidth seed source outputs linear polarization continuous laser with a wavelength of 1.5 microns, a radio frequency signal source generates a linear frequency modulation signal and sends the linear frequency modulation signal to a modulator drive, and the modulator drive loads the linear frequency modulation signal and a bias voltage to a double-parallel phase modulator; an output end of the narrow linewidth seed source is connected with the double-parallel phase modulator, the laser experiences linear frequency modulation in the double-parallel phase modulator, the output end of the double-parallel phase modulator is connected with an optical beam splitter, the output end of the optical beam splitter outputs a part of modulated laser to serve as radar local oscillation light, the output of the optical beam splitter is connected with an optical fiber amplifier, and the amplified laser is output from the output end of the optical fiber amplifier. The broadband linear frequency modulation narrow linewidth fiber laser is narrow in linewidth, large in modulation bandwidth, capable of meeting the use requirements of a synthetic aperture laser radar and a linear frequency modulation continuous wave laser radar, high in modulation speed and high in modulation linearity.

Description

technical field [0001] The invention belongs to the technical field of laser radar, and in particular relates to a wideband linear frequency modulation narrow linewidth fiber laser and a realization method thereof. Background technique [0002] The broadband linear frequency modulation technology of narrow linewidth laser is the key technology in synthetic aperture lidar and linear frequency modulation continuous wave lidar, but the development of broadband linear frequency modulation technology of solid-state laser is slow, which seriously restricts the development of lidar technology. The methods of linear frequency modulation of laser mainly include acousto-optic modulation, temperature tuning, piezoelectric ceramics, electro-optic modulation and other methods. Since the performance of the acousto-optic modulator is limited by the crystal Bragg diffraction bandwidth and the transit time of the sound wave through the beam, the frequency of the sound field can only reach th...

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Problems solved by technology

[0003] At present, the method of using a phase modulator to externally modulate the laser to achieve optical frequency tuning has been proposed, but using a 2×2MZI structure dual-parallel phase modulator directly realizes the performance of optical carrier suppression single sideband and optical wavelength shifting, and realizes broadband linearity. Frequency modulation technology, the development of 1.5 micron wavelength fast broadband linear frequency modulation narrow linewidth fiber laser scheme has not been reported

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