Method for amplifying Brillouin scattering signal by continuous laser pumping

Abstract

The invention discloses a method for amplifying a Brillouin scattering signal by continuous laser pumping. The method comprises the following steps: a pulse laser device generates laser, the laser passes through a polarization coupling mirror, a beam combiner and a 1 / 4 slide in sequence and enters a scattering medium of a scattering tank through a focus system comprising a concave lens and a convex lens, the stimulated Brillouin scattering occurs at a focal point, and a scattering signal returns backwards at an angle of 180 degrees; continuous laser generated by a continuous laser device is subjected to polarization state adjustment through a polarizer, reaches the beam combiner through a reflection mirror and is combined with the pulse laser to form a beam of laser, the laser enters the scattering medium through the focus system for pumping amplification of a stimulated Brillouin echo signal generated by the pulse laser, and the amplified scattering signal is reflected through the polarization coupling mirror and received by a detector. According to the method, the continuous laser cannot be influenced by the pulse width, so that the signal can be continuously amplified and the amplification distance is relatively long; in addition, the polarizer is added to the rear part of the continuous laser device, so that the polarization state of the continuous laser device can be controlled.

Description

technical field [0001] The invention relates to a detection technology for pumping and amplifying signals, in particular to a method for pumping and amplifying stimulated Brillouin scattering signals by using a continuous laser. Background technique [0002] Lidar has been widely used in ocean detection, and stimulated Brillouin scattering technology has also been applied to the measurement of ocean environment parameters and water body parameters. However, due to the attenuation of the laser in water, the intensity of the stimulated Brillouin scattering echo signal is greatly weakened, resulting in the limitation of the detection depth. To solve this problem, laser pumping amplification technology is applied to enhance the echo signal of stimulated Brillouin scattering. Previously, a double-cell Brillouin amplification system was proposed to amplify the Brillouin signal. The double-cell Brillouin amplification system uses two scattering cells, and the stimulated Brillouin ...

AI Technical Summary

Problems solved by technology

In the lidar system, in order to ensure the time and space resolution of the radar, the laser pulse width used to stimulate stimulated Brillouin scattering should be as narrow as possible, so the effective amplification distance is very limited

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