Self-Referencing, Spectrally, or Spatially Encoded Spectral Interferometry for the Complete Characterization of Attosecond Electromagnetic Pulses

We propose a method for the complete characterization of attosecond duration electromagnetic pulses produced by high harmonic generation in an atomic gas. Our method is based on self-referencing spectral interferometry of two spectrally sheared extreme ultraviolet pulses, which is achieved by pumping the harmonic source with two sheared optical driving pulses. The resulting interferogram contains sufficient information to completely reconstruct the temporal behavior of the electric field. We demonstrate that such a method is feasible, and outline two possible experimental configurations.

Figure 1

(a) Schematic diagram of the arrangement for measuring XUV pulses using SPIDER, where $n$ denotes harmonic order; (b) Simulated XUV-SPIDER signal generated in argon for ${\lambda }_1=800\mathrm{n}\mathrm{m},{\lambda }_2=804\mathrm{n}\mathrm{m}$, and $I=1.7\times {10}^{14}\mathrm{W}/{\mathrm{c}\mathrm{m}}^2$.

Figure 2

The spectral phase retrieved from the interferogram in Fig. 1.

Figure 3

(a) Schematic arrangement for SEA-SPIDER characterization of attosecond pulses produced by high harmonic generation. (b) Diagram showing spatial interference fringes for SEA-SPIDER, conversion to the pseudotime/$k$-space domain and sideband filtering.