TY - JOUR
T1 - A streak camera study of superfluorescence at multiple wavelengths from helium atoms excited using free electron laser pulses
AU - Harries, James R.
AU - Iwayama, Hiroshi
AU - Nagasono, Mitsuru
AU - Togashi, Tadashi
AU - Yabashi, Makina
AU - Kuma, Susumu
AU - Nakajima, Kyo
AU - Miyamoto, Yuki
AU - Ohae, Chiaki
AU - Sasao, Noboru
AU - Shigemasa, Eiji
N1 - Publisher Copyright:
© 2015 IOP Publishing Ltd.
PY - 2015/5/28
Y1 - 2015/5/28
N2 - Abstract We report the observation of superfluourescence at wavelengths (in air) of 501.6 nm, 667.8 nm, and 728.1 nm following the excitation of helium atoms with free-electron laser pulses at wavelengths of 53.7 nm (n = 3 excitation) and 52.2 nm (n = 4 excitation). The observed wavelengths of the superfluorescence pulses correspond to 1s3p-1s2s, 1s3d-1s2p, and 1s3s-1s2p transitions. Observation of superfluorescence on these transitions implies either competing cascade decays, or direct excitation of non-dipole allowed transitions. We have studied the time structure of the emitted pulses using a streak camera, and the results cannot be explained by straightforward considerations using the usual model for two-level superfluorescence.
AB - Abstract We report the observation of superfluourescence at wavelengths (in air) of 501.6 nm, 667.8 nm, and 728.1 nm following the excitation of helium atoms with free-electron laser pulses at wavelengths of 53.7 nm (n = 3 excitation) and 52.2 nm (n = 4 excitation). The observed wavelengths of the superfluorescence pulses correspond to 1s3p-1s2s, 1s3d-1s2p, and 1s3s-1s2p transitions. Observation of superfluorescence on these transitions implies either competing cascade decays, or direct excitation of non-dipole allowed transitions. We have studied the time structure of the emitted pulses using a streak camera, and the results cannot be explained by straightforward considerations using the usual model for two-level superfluorescence.
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U2 - 10.1088/0953-4075/48/10/105002
DO - 10.1088/0953-4075/48/10/105002
M3 - Article
AN - SCOPUS:84928693014
VL - 48
JO - Journal of Physics B: Atomic, Molecular and Optical Physics
JF - Journal of Physics B: Atomic, Molecular and Optical Physics
SN - 0953-4075
IS - 10
M1 - 105002
ER -