Metastable argon production via strong-field excitation

Synopsis Strong-field excitation is an exciting prospect for producing noble gas atoms in metastable states with unprecedented efficiency. This process, known as frustrated tunnel ionization, occurs after strong-field tunneling when the returning electron wavepacket recombines leaving the atom in an excited state. We investigate this excitation process using an amplified, few-cycle laser system in conjunction with an argon atomic beam.