Single-shot implementation of dispersion-scan for the characterization of ultrashort laser pulses

Abstract

Abstract:We demonstrate a novel, single-shot ultrafast diagnostic, based on the dispersionscan (d-scan) technique. In this implementation, rather than scanning wedges to vary the dispersion as in standard d-scan, the pulse to be measured experiences a spatially varying amount of dispersion in a Littrow prism. The resulting beam is then imaged into a secondharmonic generation crystal and an imaging spectrometer is used to measure the twodimensional trace, which is analyzed using the d-scan retrieval algorithm. We compare the single-shot implementation with the standard d-scan for the measurement of sub-3.5-fs pulses from a hollow core fiber pulse compressor. We show that the retrieval algorithm used to extract amplitude and phase of the pulse provides comparable results, proving the validity of the new single-shot implementation down to near single-cycle durations.

Universal route to optimal few- to single-cycle pulse generation in hollow-core fiber compressors

“…The residual TOD which appears in the optimal output pulses can be further compensated for, not only to reduce the output pulse duration but also to increase the amount of energy in the output pulse. This can be done, for example, 7/13 by using an adequate transparent medium such as water [42,44,45], z-cut KDP [43] or z-cut ADP [6], which directly enables achieving high-quality pulses in a more strict single-cycle regime. In spite of the relatively small magnitude of this TOD (e.g., -40 fs 3 reported in Ref.…”

“…An optimization algorithm is then used to retrieve the spectral phase of the pulse from the measured d-scan trace and calibrated linear spectrum [41]. A recent approach to d-scan retrieval can also be used to obtain the pulse amplitude and phase from the measured trace [43], but in this case, the trace itself must be calibrated.D-scan has been successfully demonstrated with few-cycle pulses since its inception [22,41], and over octave-spanning single-cycle pulses have been measured directly with SHG d-scan [6,40,[43][44][45]. Apart from its robustness and performance, another important advantage of d-scan is the fact that it directly results in very intuitive traces that provide useful guiding information on the quality of the achieved pulse compression, which motivates our use of the d-scan trace as a diagnostic tool.…”

“…D-scan has been successfully demonstrated with few-cycle pulses since its inception [22,41], and over octave-spanning single-cycle pulses have been measured directly with SHG d-scan [6,40,[43][44][45]. Apart from its robustness and performance, another important advantage of d-scan is the fact that it directly results in very intuitive traces that provide useful guiding information on the quality of the achieved pulse compression, which motivates our use of the d-scan trace as a diagnostic tool.…”

Deep learning reconstruction of ultrashort pulses from 2D spatial intensity patterns recorded by an all-in-line system in a single-shot

“…This endows our technique with possibly greater % robustness that can make it advantageous for real time probing of ultrafast processes and under noisy conditions. Also, it is important to note that our technique does not suffer from the stringent physical restrictions characteristic of other single-shot methods, for example, on the time-bandwidth product [14] or on the spatial beam profile [20], avoiding these limitations facilitates greater dynamic range and robustness.…”

“…However, in some experiments [12,13], the probed pulse is not part of a train of identical pulses, hence it is often desired to characterize a pulse using a single-shot characterization method. Indeed, single-shot variants of FROG (termed GRENOUILE [14]) and of d-scan [15] were developed. In GRENOUILE, a Fresnel bi-prism splits an incoming pulse beam into two non-collinear stripe beams, where the delay between the pulses is mapped to a spatial axis.…”