Femtosecond differential optical Kerr gate and imaging device and method based on the optical Kerr gate

Abstract

The invention discloses a femtosecond differential optical Kerr gate and an imaging device and method based on the optical Kerr gate. A probe light path is provided with a target to be detected, a scattering medium, the femtosecond differential optical Kerr gate and two single-pulse triggering CCDs in sequence, wherein the femtosecond differential optical Kerr gate is composed of a polarizer, an optical Kerr medium, a first beam splitting piece, two quarter-wave plates and two analyzers. The polarization direction of the polarizer is the same as the polarization direction of femtosecond detecting pulse light, the positive heterodyne angle ranging from 2 degrees to 5 degrees is formed by the polarization direction of one analyzer and the polarization vertical direction of the polarizer, and the negative heterodyne angle ranging from 2 degrees to 5 degrees is formed by the polarization direction of the other analyzer and the polarization vertical direction of the polarizer. A switching light path is provided with a half wave plate and an optical delay line. The femtosecond switching pulse light coincides with the femtosecond probe pulse light in the optical Kerr medium. A positive heterodyne single-pulse gating image and a negative heterodyne single-pulse gating image are obtained on the two single-pulse triggering CCDs respectively, subtraction is carried out on the two images to obtain a femtosecond differential optical Kerr gate single-pulse gating image of the target to be detected. The single-pulse imaging with the high signal to noise ratio is achieved, and the femtosecond differential optical Kerr gate and the imaging device and method based on the optical Kerr gate have the advantages that the time resolution, the image contrast and the system resolution are high.

Description

technical field [0001] The invention belongs to the technical field of ultra-fast imaging and measurement, and relates to a femtosecond differential optical Kerr gate and an imaging device and method based on the optical Kerr gate. Background technique [0002] The rapid development of femtosecond lasers has promoted the progress of femtosecond technology, such as femtosecond optoelectronic devices and optical communication systems, ultrashort pulse measurement systems, and ultrafast response measurements of new materials, ultrafine micromachining, etc. The ultra-fast imaging and measurement technology based on femtosecond laser has high time resolution and can be used to study ultra-short physical, biological and chemical reaction processes. It has important application value in the field of transient process research such as high-speed collision, detonation process, high-voltage discharge, and visual mechanism. [0003] The optical Kerr gate gating method based on the fem...

AI Technical Summary

Problems solved by technology

When using femtosecond heterodyne optical Kerr gate imaging technology to implement single-pulse transient imaging, this background noise will increase the imaging signal-to-noise ratio, affect the improvement of imaging contrast, and even make it impossible to achieve single-pulse imaging

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