| Abstract [eng] |
The temporal characterization of laser pulses is one of the first and most essential steps in studying ultrafast light and matter interactions. Therefore, it is not surprising that we have multiple characterization techniques based on either nonlinear material response (e.g., FROG, SPIDER, GRENOUILLE, etc. [18]) or the utilization of an ultrashort gating pulse (e.g., photoionization "streaking," petahertz oscilloscope, etc. [4, 5]). In the former case, the spectral range that can be effectively utilized is restricted due to phase-matching condition, while the latter case demands intricate and costly vacuum systems. This stimulates the exploration of alternative methods for measuring pulse duration, leading to the emergence of the TIPTOE measurement methodology. The objective of this scientific work is to measure the duration of an ultrashort pulse in the near-infrared region, by reconstructing its electric field and spectral characteristics using a single-shot TIPTOE measurement methodology implemented in a silicon camera, and compare the measurement results with the FROG methodology. Therefore, in this work, to explore the limits of the TIPTOE characterization method, three differently phase- modulated pulses were reconstructed, where spectral phase analysis confirmed the accurate reconstruction of the TIPTOE retrieved spectral phase, which contained information about the dispersion coefficients of the medium through which the pulse propagated. Furthermore, the temporal and spectral characteristics of the TIPTOE-reconstructed pulse were compared with the frequency-resolved optical gating (FROG) measurement performed using a ∼10 μm thickness BBO crystal, demonstrating good agreement between the respective characterization methods. Moreover, to verify the reliability and application limits of the TIPTOE characterization methodology, the theoretical TIPTOE modeling was carried out for various laser pulse parameters. The modeling results were used to demonstrate the detailed reconstruction of two differently phase-modulated pulses and evaluate the retrieval accuracy. Additionally, by assessing the retrieval errors of the TIPTOE characterization method for different pulse spectrum widths and pulse duration-bandwidth products (TBP), a "map" of reconstruction errors was calculated, illustrating the dependence of the TIPTOE retrieval error on these pa- rameters and defining the operational limits of the TIPTOE characterization method. From the calculated pulse retrieval error maps, it was determined that the retrieval error is independent of the pulse spectrum width, but depends on the pulse phase modulation (TBP) and employed TIPTOE nonlinearity . Finally, it was estimated that in our implemented TIPTOE characterization setup, we can measure laser pulses that are temporally broadened up to 2.8 times without significant reconstruction errors. |
