Continuous Lyman-alpha generation by four-wave mixing in mercury for laser cooling of antihydrogenThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

Cooling antihydrogen atoms is important for future experiments both to test the fundamental CPT symmetry by high resolution laser spectroscopy and also to measure the gravitational acceleration of antimatter. Laser cooling of antihydrogen can be done on the strong 1S–2P transition at the wavelength of Lyman-alpha (121.6 nm). A continuous wave laser at the Lyman-alpha wavelength based on solid-state fundamental lasers is described. By using a two-photon and a near one-photon resonance a scan across the whole phase matching curve of the four-wave mixing process is possible. Furthermore the influence of the beam profile of one fundamental beam on the four-wave mixing process is studied.

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Spectral–temporal biphoton waveform of photon pairs from cascade-type warm atoms

Scientific Reports ◽

10.1038/s41598-020-73610-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Jiho Park ◽

Taek Jeong ◽

Han Seb Moon

Keyword(s):

Photon Counting ◽

Four Wave Mixing ◽

Single Photons ◽

Wave Mixing ◽

Mixing Process ◽

Time Resolved ◽

Two Photon ◽

Photon Pairs ◽

Cascade Type

Abstract We investigate the spectral–temporal biphoton waveforms of the photon pairs emitted from cascade-type two-photon-coherent warm 87Rb atoms via the spontaneous four-wave mixing process in the 5S1/2–5P3/2–5D5/2 transition, under the condition of the different detuning frequencies (symmetric detuning conditions of ± 1 GHz) of the pump and coupling lasers relative to the 5P3/2 state. In both detuning cases corresponding to ± 1 GHz, the biphoton temporal waveforms and biphoton spectral waveforms of the photon pairs are measured by means of time-resolved coincidence photon counting and stimulated measurements, respectively. Although photon-pairs were generated using opposite detunings, we confirm that the spectral–temporal biphoton waveforms of the photon pairs are very similar. Furthermore, we observe Hong–Ou–Mandel interference with 82% visibility with the two independent heralded single photons.

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Monochromatic Conical IR Emission from Decaying KrF Laser Filaments in Xenon as Coherent Stimulated Four-Wave Mixing Process

Photonics ◽

10.3390/photonics8020047 ◽

2021 ◽

Vol 8 (2) ◽

pp. 47

Author(s):

Igor V. Smetanin ◽

Alexey V. Shutov ◽

Nikolay N. Ustinovskii ◽

Vladimir D. Zvorykin ◽

Anna V. Bogatskaya ◽

...

Keyword(s):

Transverse Relaxation Time ◽

Four Wave Mixing ◽

Theoretical Background ◽

Wave Mixing ◽

Mixing Process ◽

Optical Phenomenon ◽

Coherent Interaction ◽

Conical Emission ◽

Krf Laser ◽

Ir Emission

We develop theoretical background for the new nonlinear optical phenomenon of narrowly directed monochromatic IR conical emission which has been recently observed when 248-nm UV filaments propagate in xenon (V. D. Zvorykin, et al., Laser Phys. Lett. 13, 125404 (2016)). We treat it as coherent stimulated four-wave mixing process in which two pump KrF laser photons are converted into the coupled pair of resonance IR(828 nm) and VUV (147 nm) photons through 5p5(2P3/2)6p[1/2]0→5p5(2P3/2)6s[3/2]1o and 5p5(2P3/2)6s[3/2]1o→1S0 transitions. We explore the coherent interaction regime which proceeds at a time scale shorter than transverse relaxation time T2. The momentum and energy conservation laws determine the characteristic angle of conical emission. We find that the threshold of this coherent process is determined by the KrF laser pump pulse area.

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