1.
Phys Rev Lett
; 123(21): 213904, 2019 Nov 22.
Artigo
em Inglês
| MEDLINE
| ID: mdl-31809175
RESUMO
Intense, mutually coherent beams of multiharmonic extreme ultraviolet light can now be created using seeded free-electron lasers, and the phase difference between harmonics can be tuned with attosecond accuracy. However, the absolute value of the phase is generally not determined. We present a method for determining precisely the absolute phase relationship of a fundamental wavelength and its second harmonic, as well as the amplitude ratio. Only a few easily calculated theoretical parameters are required in addition to the experimental data.