Sweep frequency linearization and coherent enhancement method based on composite optical phase-locked fiber laser

Abstract

The invention discloses a sweep frequency linearization and coherent enhancement method based on a composite optical phase-locked fiber laser. The method comprises the following steps of: in an open-loop state of a sweep frequency laser light source system, obtaining a group of control voltage signals through calculation, and preliminarily correcting the response linearity of the sweep frequency fiber laser under the driving of the control voltage signals; and on the basis of the open-loop state of the frequency sweep laser light source system, adding a piezoelectric ceramic driving loop and an acousto-optic frequency shifter loop to form a closed-loop state, making frequency sweep light signals pass through a Mach-Zehnder interference structure and a photoelectric detector to generate beat frequency signals with frequency sweep information, and frequency sweep driving signals, outputting error signals through a digital phase discriminator, loading the error signals to the control voltage signals to form new feedback control signals, and making the piezoelectric ceramic driving loop and the acousto-optic frequency shifter loop enter a closed-loop feedback control state under the driving of the new feedback control signals. By adopting the composite optical phase locking technology, the sweep frequency linearization and coherence of the optical fiber laser are enhanced at the same time.

Description

technical field [0001] The present invention relates to the technical field of phase-locked-loop fiber lasers, and more specifically relates to a frequency-sweeping linearization and coherent enhancement method based on composite optical phase-locked fiber lasers. Background technique [0002] The optical frequency modulation continuous wave technology is to modulate the frequency of the continuous wave with a triangular wave with a fixed slope, so that the regularly changing reflected signal and the local signal will generate a continuous beat frequency signal. The frequency of the beat frequency signal depends on the target distance, and the amplitude depends on Based on the echo signal strength, it is a technology that can simultaneously measure the distance of the target and the echo strength through spectrum analysis. At its heart is a linearly swept laser source. [0003] Compared with traditional lasers, the gain bandwidth of fiber lasers and doped fibers is much lar...

AI Technical Summary

Problems solved by technology

[0007] In view of this, the present invention provides a method based on composite optical phase-locked fiber laser frequency sweep linearization and coherence enhancement method, which can simultaneously suppress fiber laser frequency sweep nonlinearity and phase noise, and solve the problem that the system phase-locking time is long , the problem of residual nonlinearity

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