Theoretical And Experimental Study On Spectral Phase Interferometry For Direct Electric-field Reconstruction

In this thesis, theoretical and experimental studies on Spectral PhaseInteferometry for Direct Electric-Field Reconstruction (SPIDER) were presented. Themain contents are as follows: 1. The development and application of femtosecond pulses characterizations were introduced. The background of the SPIDER technique was described and the theory of phase retrieving was demonstrated. 2. The correlations among three important parameters in SPIDER, the time delay τbetween the test pulse replicas, the frequency shear Ω and the second-order dispersion φ& determined from a stretcher, are investigated. The results show & that there are different optimum time delayτfor different test pulse with a fixed φ& . The measurement maybe fail if the frequency shear Ω that is direct & proportion to the time delayτbecomes too large to meet the condition of the sum-frequency. Therefore, for the different widths of pulses, the magnitude of φ& should be properly adjusted for selecting the optimumτ. & 3. The model of spectral filter of the nonlinear crystal in a SPIDER apparatus was constructed. The relationship between the bandwidth of the conversion efficiency of BBO crystal and the crystal thickness was calculated. The choice range of the BBO thickness adapting to the different widths of pulses was discussed. 4. The SPIDER apparatus was set up and the complete retrieval algorithm of SPIDER was performed with a LABVIEW code of NI. The experimental results for characterizing femtosecond pulses from a Ti:sapphire oscillator with this SPIDER apparatus were demonstrated. At last the realization of real-time SPIDER including optical parts and the LABVIEW program was completed.