Spatio-temporal couplings in ultrashort laser pulses

Abstract

The electric field of an ultrashort laser pulse often fails to separate into a product of purely temporal and purely spatial factors. These so-called spatio-temporal couplings constitute a broad range of physical effects, which often become important in applications. In this review, we compile some recent experimental and theoretical work on the understanding, avoidance and applications of these effects. We first present a discussion of the characteristics of pulses containing spatio-temporal couplings, including their sources, a mathematical description and the interdependence of different couplings. We then review different experimental methods for their characterization. Finally, we describe different applications of spatio-temporal couplings and suggest further schemes for their exploitation and avoidance.

Multi-μJ harmonic emission energy from laser-driven plasma

“…This points to the conclusion that it should correlate to the spatial properties of the laser pulse. A plausible explanation is the spatiotemporal coupling (STC) of the laser beam [33]. It is to be noted here that the laser focus shown in the inset of Fig.…”

Attosecond Lighthouses: How To Use Spatiotemporally Coupled Light Fields To Generate Isolated Attosecond Pulses

“…Under the effect of even simple optical components, the spatial properties of these beams can vary over the duration of the light pulse [1]. In this letter, we show how such spatio-temporally coupled electromagnetic fields can be exploited to produce an attosecond lighthouse, i.e.…”

“…Ultrashort light beams are said to exhibit spatiotemporal couplings (STC) when their spatial properties depend on time, and conversely [1] -i.e. their electric field E(x, y, z = z 0 , t) = E 1 (t)E 2 (x, y).…”

“…In contrast, the problem is still unsolved experimentally for HHG on plasma mirrors [8][9][10], one of the promising processes to obtain the next generation of attosecond light sources [11,12]. We describe here how STC provide a new approach to this problem, of unprecedented simplicity, generality and potential : one of the most basic types of STC, wavefront rotation [1] (WFR), can be exploited to generate a collection of single attosecond pulses in angularly well-separated light beams -an attosecond lighthouse-even with relatively long laser pulses.…”

“…Out of focus, this Position STC takes a different form, called pulse front tilt [1], which corresponds to an E-field of the form (assuming Gaussian profiles in time and space) :…”