Simultaneous Measurements of Super-Radiance at Multiple Wavelengths from Helium Excited States: I. Experiment

@article{Nakajima2014SimultaneousMO,
  title={Simultaneous Measurements of Super-Radiance at Multiple Wavelengths from Helium Excited States: I. Experiment},
  author={K. Nakajima and James R Harries and Hiroshi Iwayama and Susumu Kuma and Yuki Miyamoto and Mitsuru Nagasono and Chiaki Ohae and Tadashi Togashi and Makina Yabashi and Eiji Shigemasa and Noboru Sasao},
  journal={Journal of the Physical Society of Japan},
  year={2014},
  volume={84},
  pages={054301-054301}
}
In this paper, we report the results of measurements of the intensities and delays of super-radiance decays from excited helium atoms at multiple wavelengths. The experiment was performed using extreme ultraviolet radiation produced by the free electron laser at the SPring-8 Compact SASE Source test accelerator facility as an excitation source. We observed super-radiant transitions on the 1s3p → 1s2s (λ = 502 nm), 1s3d → 1s2p (λ = 668 nm), and 1s3s → 1s2p (λ = 728 nm) transitions. The pulse… 
7 Citations

Simultaneous Measurements of Superradiance at Multiple Wavelength from Helium Excited States: II. Analysis

Previous experimental studies of superradiance (SR) in multi-level systems have been explainable using the predictions of the well-known simple two-level SR model. However our recent study [K.

Collective effects in the radiative decay of the 2P1 state in helium

We present a theoretical study of He 2 P –2 S emission from a helium gas, where the upper atomic state is prepared by a 100 fs laser pulse resonant with the 1 S–2 P transition. The fluorescence

Time-resolved quantum beats in the fluorescence of helium resonantly excited by XUV radiation

We report on the observation of time-resolved quantum beats in the helium fluorescence from the transition 1s3p → 1s2s, where the initial state is excited by XUV free electron laser radiation. The

Extreme Ultraviolet Superfluorescence in Xenon and Krypton

We present a comprehensive experimental and theoretical study on superfluorescence in the extreme ultraviolet wavelength regime. Focusing a high-intensity free-electron laser pulse in a cell filled

Superfluorescence/Superradiance in Helium Following Free-Electron Laser Excitation

We discuss the observation of superfluorescence following the excitation of helium atoms with pulses from a free-electron laser. From semi-classical simulations and consideration of transition

Evidence of Extreme Ultraviolet Superfluorescence in Xenon.

A novel theoretical approach, based on a full quantum treatment of the atomic system and the irradiated field, shows quantitative agreement with the experiment and supports the interpretation of superfluorescence in the spectral domain.

References

SHOWING 1-10 OF 13 REFERENCES

Observation of free-electron-laser-induced collective spontaneous emission (superfluorescence).

To the knowledge, this is the first observation of superfluorescence following pumping in the extreme ultraviolet wavelength region, and extension of the technique to the generation of extreme ultraviolet and x-ray superfluorescence pulses should be straightforward by using suitable atomic systems and pump wavelengths.

Stable operation of a self-amplified spontaneous-emission free-electron laser in the extremely ultraviolet region

We achieved stable operation of a free-electron laser (FEL) based on the self-amplified spontaneous-emission (SASE) scheme at the SPring-8 Compact SASE Source (SCSS) test accelerator in the extremely

Observation of superradiance in Rb vapour

Using laser excitation of the 62P levels in the natural isotopic mixture of Rb atoms, modulation of superradiance intensity from some transitions to the lower levels was observed. On the transition

Compact XFEL and AMO sciences: SACLA and SCSS

The concept, design and performance of Japan's compact free-electron laser (FEL) facilities, the SPring-8 Compact SASE Source test accelerator (SCSS) and SPring-8 Angstrom Compact free electron LAser

A compact free-electron laser for generating coherent radiation in the extreme ultraviolet region

Free-electron lasers can produce powerful pulses of radiation at very short wavelengths, even in the hard-X-ray region. In general, however, they comprise facilities several kilometres in length. A

Superradiating 4P-4S-3P cascade of sodium vapour arising on the leading edge of the exciting laser pulse

Investigations of the superradiating cascade of sodium vapour 4P-4S-3Pλ1 = 2.21 µm andλ2=1.14 µm) arising on the leading edge of the exciting laser pulse were carried out. The dependences of the

Superradiant cascading effects in rubidium Rydberg levels

The authors report the first observation of superradiant cascading effects in rubidium Rydberg levels. For excited state densities of the order of 1010 cm-3, superradiant emissions drastically modify

Coherence in Spontaneous Radiation Processes

By considering a radiating gas as a single quantum-mechanical system, energy levels corresponding to certain correlations between individual molecules are described. Spontaneous emission of radiation