Single-frame measurement of complex laser pulses tens of picoseconds long using pulse-front tilt in cross-correlation frequency-resolved optical gating

Abstract

We demonstrate the use of pulse-front tilt (PFT) in cross-correlation frequency-resolved optical gating (XFROG) implemented in polarization-gate geometry to measure arbitrary complex ultrashort pulses tens of picoseconds long on a single-camera frame with the potential for a single-shot measurement. The PFT is generated by a diffraction grating. We measured chirped double pulses separated by 4.7 and 24 ps with fine details and accurately retrieved them using the standard XFROG retrieval algorithm. The temporal range of our device is 28 ps, an order of magnitude longer than available from standard single-shot FROG devices without PFT.

An experimental study of intensity‐phase characterization of femtosecond laser pulses propagated through a polymethyl methacrylate

“…14 Here, we report the comprehensive intensity-phase characterization study of ultrashort pulses propagated through a 10 mm thick PMMA sample by fully characterizing the input and output pulses using FROG and XFROG techniques. For quick and reliable data acquisition and analysis, we adopted the automated multi-shot second-harmonic generation (SHG) FROG 15 and the multi-shot sum frequency generation (SFG) XFROG 16,17 techniques. The SHG-FROG and SFG-XFROG techniques are preferred because of their versatility, sensitivity, and ease of implementation.…”

Characterizing ultrashort laser pulses by the rotational Doppler effect

“…Nevertheless, single-shot arrangements based on these processes suffer from geometrical smearing [26] because the signal does not propagate along the bisector of the beams. Furthermore, single-shot measurements of UV pulses by PG [23,27] or TG [21] FROG need an input energy of a few tens or hundreds of μJ. A variant of SPIDER, the SD-SPIDER [28], operating at the fundamental frequency has also been reported, but the SD process is not phasematched and the device measures the phase of the second harmonic (and not the one of the pulse), implying an elaborate retrieval procedure.…”

Complete characterization of a spatiotemporally complex pulse by an improved single-frame pulse-measurement technique

“…While it is possible to measure the spatial profile averaged over time and the temporal profile averaged over space, ultrafast lasers unfortunately suffer from an abundance of spatiotemporal couplings or distortions in which a pulse's temporal and spectral intensity and phase vary with transverse position, or equivalently, the spatial intensity and phase vary with time or frequency [1]. Some spatiotemporal couplings are useful in such applications as attosecond pulse generation, spacetime focusing, pulse compression, and nonlinear optics [2][3][4][5][6][7], but most are not. For example, in Kerr-lens mode-locked lasers, the output mode size depends on frequency [8], and, even if it does not, it necessarily will at a focus due to the wavelength dependence of a focal spot size for a given input spot size.…”