Observation of ultrafast phenomena by holography using femtosecond pulsed laser and its application

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We developed an ultrafast imaging system to record and observe the propagation of femtosecond light pulses in space and time as form of frameless motion picture. To obtain the motion picture, light-in-flight recording of holography using femtosecond pulsed laser was applied. We observed a propagating femtosecond light pulse through a dispersion prism and light pulse train generated from the integrated array illuminator. The temporal and spatial behavior of such ultrashort light pulse in the prism and from the array illuminator was clearly observed. In the experiment, we have found that the shape of the reconstructed image is changed and distorted depending on the observation position when the observation position is moved along the vertical direction of the hologram. The dependence of the reconstructed image characteristics on the observation condition was analyzed both theoretically and numerically. Also, the shape of the reconstructed image obtained by the experiment is analyzed. An … More experiment to verify the theory was conducted using a femtosecond pulsed laser. We also proposed the method of compensation of the distortion of the reconstructed image.We also succeeded in observing a femtosecond light pulse propagating in three-dimensional space. The experiments were carried out to record and reconstruct the femtosecond light pulse propagating in the jelly made of gelatin and succeeded in observing the femtosecond light pulse. We found that the reconstructed image of the femtosecond light pulse propagating in the jelly was flipped compared to the true pulse front. We discussed the cause of the flip and developed a model to analysis the shape of the reconstructed image. The shape of the reconstructed image was also simulated numerically. The results of the simulation almost agreed with the experimental results.This technology achieves a temporal microscope with more than 10^<10> magnification and will open the possibility for observing and analyzing the various ultrafast phenomena. It will become a powerful tool for directly observing ultrafast dynamics of atoms and molecules when the proposed technique is applied to the electron holography or X-ray holography. Less