Photon echo of homogeneous assembly of atoms

A.I. Alekseyev, Igor V. Yevseyev

Yutaka Nagasawa

G. N. Nikolaev

In investigations of predicted new types of photon echoes — an echo from a homogeneous ensemble of atoms and an echo of a single light pulse — have established that the magnitude and form of these new types of photon echoes are completely determined by the type of optical transition and by the “area” and polarization of the exciting light pulses (and the form can be controlled by varying the magnetic field). It is also established that the echo amplitude decreases for both small (compared to 1) and large light-pulse areas, and the optimal areas for which the maximum echo is obtained have been found. Investigations show that such photon echoes can also appear under conditions when an ordinary photon echo is absent (in atomic or molecular gases at high pressure, in the far-IR region of the spectrum, from cooled trapped atoms or ions, and so on).

T. V. Smirnova, Olga M. Fedotova, Oleg Kh Khasanov

Н. Н. Рубцова, Хворостов Евгений Борисович, Sergei A. Kochubei +1 more

Abstract A collision-induced photon echo (PE) was formed at the 174 Yb (6s 2 ) 1 S 0 —(6s6p) 3 P 1 transition by two resonant radiation pulses polarized linearly and mutually orthogonally. The noble gases He, Ne, Ar, Kr and Xe were used as collision partners for excited 174 Yb atoms. The nonmonotonous decay kinetics of collision-induced PE was detected. The ordinary PE formed by identical linear polarization pulses at the same experimental conditions showed a monotonous decay for the time delays between 80 and 300 ns. The anisotropy parameters for the collisions of 174 Yb atoms with Ne, Ar, Kr and Xe atoms increase with the buffer atom mass and are between 15% and 20% of the corresponding homogeneous line broadening values.

P. Darejeh

The photon echo experiment is a method of measuring the homogeneous dephasing time (T2) from which the homogeneous linewidth of an optical transition can be calculated.In this thesis, the theories of linewidths of transitions and of the development of a photon echo are presented.Also discussed is the experimental setup by which the first photon echoes in the rare-earth terbium were observed and measured.The decays of echo intensity with laser pulse separation at the externally applied fields of 45 KG and 25 KG were plotted and from these plots a homogeneous dephasing time of HO nanoseconds was calculated.Data at 15 KG were taken, but because of the non-exponential behavior of the decay, Tj was not calculated.At 0 KG, no echo was observed, implying a decrease of the dephasing time below 15 KG.