Compact single-shot d-scan setup for the characterization of few-cycle laser pulses

Abstract

We present a compact implementation of the ultrashort pulse measurement technique based on dispersion scans (d-scan), allowing single-shot measurement of few-cycle pulses. The main novelty in our design, making our setup extremely compact and simple, is the use, after a prism, of a spherical mirror in an off-axis geometry. The intentionally introduced strong astigmatism makes it possible to image the output of the crystal in one direction while focusing it in the other direction, resulting in the output face of the prism being imaged into a line in the second-harmonic crystal. The technique is validated by comparing measured dispersion scans, retrieved spectral phases and temporal profiles of this single-shot system with standard d-scan results.

Characterizing ultrashort laser pulses with second harmonic dispersion scans

“…An elegant solution is to let the beam pass the prism first and then reflect off a spherical mirror under a large off-axis angle, introducing strong astigmatism. Adjusting the angles and distances between the prism, the mirror, and the SHG crystal allows us to focus the beam in one dimension while imaging the face of the prism in the other onto the crystal, which results in a more compact and space-efficient design [69]. A similar, but even simpler configuration, is depicted in Fig.…”

“…In both cases, the SHG signals were detected with home-made imaging spectrometers, using a compact, crossed Czerny-Turner design [72], relying on divergent illumination of the grating in order to correct for astigmatism of the imaging path [73,74]. More information on the spectrometer design, e.g., distances and angles between components, can be found in [69]. A cylindrical lens before the CCD sensor [75] was added for additional aberration correction.…”

Single-shot Dispersion Sampling for Optical Pulse Reconstruction

“…Another important feature that distinguishes different pulse characterization techniques is their ability to reconstruct the temporal evolution of a single laser pulse. Although the original dispersion scan was designed as a multi-shot technique, several single-shot modifications have been implemented [12][13][14][15]. Here, we demonstrate a novel method in which several reflections of the same pulse will experience each a different amount of dispersion.…”

Single-shot d-scan technique for ultrashort laser pulse characterization using transverse second-harmonic generation in random nonlinear crystals

“…Indeed, high-power lasers are increasingly common [8], and, due to their low repetition rate and pulse-to-pulse variations, single-shot methods are crucial for their characterization. In order to adapt the d-scan technique to this scenario, single-shot architectures have been proposed Letter [9,10]. These approaches are wedge-based, with a limited amount of introduced dispersion, which means that pulses with Fourier-limited durations larger than 30-40 fs are difficult to measure.…”

“…In addition, the application range may be extended towards longer Fourier-limited pulse durations by simply increasing the medium length, and, hence, the amount of dispersion that can be applied to the pulse. We should point out that, in contrast to other single-shot techniques [9,10,19], the beam does not have to be spatially homogeneous, and the diagnostic can be used to measure the pulse at different sampling positions within the beam.…”