A Broadband Linear Frequency Modulation Narrow Linewidth Fiber Laser and Its Realization Method

Abstract

The invention discloses a wideband linear frequency modulated narrow linewidth fiber laser and its realization method, which includes a narrow linewidth seed source outputting a linearly polarized continuous laser with a wavelength of 1.5 microns, a radio frequency signal source generating a linear frequency modulation signal, and sending it to a modulator driver , the modulator driver loads the linear frequency modulation signal and bias voltage to the dual parallel phase modulator; the output terminal of the narrow linewidth seed source is connected to the dual parallel phase modulator, and the laser undergoes linear frequency modulation in the dual parallel phase modulator, and the dual parallel phase modulator The output end of the phase modulator is connected to the fiber beam splitter, and the output part of the output end of the fiber splitter is partially modulated laser as the radar local oscillator light, the output of the fiber beam splitter is connected to the fiber amplifier, and the amplified laser is output from the output port of the fiber amplifier. The invention has narrow line width and wide modulation bandwidth, meets the requirements of synthetic aperture laser radar and linear frequency modulation continuous wave laser radar, fast modulation speed and high frequency 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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