Simultaneous lasing of Ni K α and Cu K α lasers from an alloy foil irradiated with an intense X-ray free-electron laser pulse

Key Points

• The study aims to achieve simultaneous lasing of two different K α emissions from a Cu–Ni alloy.
• Irradiation of a Cu–Ni alloy foil with an intense X-ray free-electron laser pulse
• Induction of population inversion to enable lasing
• Measurement of K α emissions at specific photon energies
• Simultaneous lasing observed at photon energies of 7.48 keV (Ni K α 1) and 8.05 keV (Cu K α 1)
• Demonstration of multi-color lasing from a single XFEL source