NEW INTER-RYDBERG TRANSITIONS OF NO REVEALED BY THE LASER-INDUCED AMPLIFIED SPONTANEOUS EMISSION

Amplified spontaneous emission (ASE) from single rotational levels of Rydberg states, 4p sigma M (2) Sigma(+), 4p pi K (2) Pi, 5s sigma S (2 ) Sigma(+), 4d sigma O (2) Sigma(+), 4d pi O' (2) Pi, 5p sigma R (2) S igma(+), and 5p pi Q (2) Pi of NO molecules has been investigated thro ugh optical-optical double resonance excitation via the A (2) Sigma(+) state. Several new inter-Rydberg transitions were identified in the m idinfrared region. The rotational structure in dispersed ASE spectra w as resolved completely, which provided detailed information on cascadi ng radiative relaxation processes among Rydberg states. (C) 1998 Ameri can Institute of Physics. [S0021-9606(98)02603-8].