Double-switching-pulse type femtosecond optical Kerr-gate and implementation method thereof

Abstract

The invention discloses a double-switching-pulse type femtosecond optical Kerr-gate and an implementation method thereof. The double-switching-pulse type femtosecond optical Kerr-gate and the implementation method thereof have the advantages that switching pulse of a traditional optical Kerr-gate is divided into two beams, an optical path of a first switching pulse beam is as same as traditional switching light, a polarization direction of a second switching pulse beam is adjusted to be perpendicular to a first switching light polarization direction through a half-wave plate, and attenuation slices and optical delay lines can adjust the intensity and the optical length; the second switching pulse beam is introduced, the intensity and relative delay time of the second switching pulse beam are adjusted continuously relatively to the first switching pulse beam, and then the optical Kerr-gate is effectively controlled by the second switching pulse beam in a first switching pulse excitation turn-off phase, so that transmittance of the optical Kerr-gate can mainly depend on the first switching pulse beam, switching-off time of the optical Kerr-gate is greatly shortened under regulation of the second switching pulse beam, and high transmittance and ultrafast switching time of the femtosecond optical Kerr-gate are achieved.

Description

technical field [0001] The invention belongs to the technical field of ultra-fast imaging and measurement, and relates to a double-switch pulse femtosecond optical Kerr gate and a realization method thereof. Background technique [0002] The development of ultra-fast imaging and measurement technology has important application value in the research fields of high-speed collision, detonation process, high-voltage discharge, visual mechanism and other transient processes. Generally, high time-resolved imaging from milliseconds to sub-picoseconds can be achieved by using photoelectric technology. Using ultra-fast imaging technology based on photonic technology, such as femtosecond holographic imaging and nonlinear optical gate imaging technology. [0003] Optical Kerr gate imaging technology is a typical nonlinear optical gate imaging technology. This imaging technology uses the optical shutter constructed by the optical Kerr effect, which is usually called an optical Kerr ga...

AI Technical Summary

Problems solved by technology

For example, the most commonly used optical Kerr medium carbon disulfide, the main source of the third-order nonlinear optical effect is the molecular reorientation effect. When the switching pulse excitation disappears, it will have a longer molecular relaxation time, resulting in carbon disulfide as the Temporal resolution of gated imaging is limited by the increased closing time of the optical Kerr gate of the medium

On the other hand, if the optical Kerr gate uses an optical Kerr medium whose nonlinear response is entirely derived from the electronic response, such as quartz glass, its switching time will be very fast, mainly limited by the width of the switching pulse, but the optical properties of such materials The nonlinear strength is often weak, and the formed optical Kerr gate has a low signal transmittance under the same conditions

Images