Light storage in an optically thick atomic ensemble under conditions of electromagnetically induced transparency and four-wave mixing

We study the modification of a traditional electromagnetically induced transparency (EIT) stored light technique that includes both EIT and four-wave mixing (FWM) in an ensemble of hot Rb atoms. The standard treatment of light storage involves the coherent and reversible mapping of one photonic mode onto a collective spin coherence. It has been shown that unwanted, competing processes such as four-wave mixing are enhanced by EIT and can significantly modify the signal optical pulse propagation. We present theoretical and experimental evidence to indicate that while a Stokes field is indeed detected upon retrieval of the signal field, any information originally encoded in a seeded Stokes field is not independently preserved during the storage process. We present a simple model that describes the propagation dynamics of the fields and the impact of FWM on the spin wave.Comment: 13 pages, 10 figure

Business education as the engine of socio-economic change in former soviet countries: the Belarusian case

The article is devoted to some new areas of business education in the Republic of Belarus whose emergence is a reaction to demand of the national economy in the course of social and economic development of the country at the beginning of the XXIst century. Opening of specialties of the second level of higher education (magistracy) is a result of the scientific researches carried out in the Academy of Management under the aegis of the President of the Republic of Belarus in 2009-2014yesBelgorod State National Research Universit

Self-assessed intelligence, personality, and psychometric intelligence: preliminary validation of a model with a selected student population

In the current study, self-assessed intelligence (SAI) is presented as a multidimensionalconstruct related both to personality and to psychometric intelligence. Onthe basis of data obtained from a Russian student sample (N = 496), the authorsvalidate a structural model in which SAI acts as a mediating variable between latentvariables of measured IQ and the trait of acceptance of uncertainty. Evidencefor signifi cant gender diff erences in SAI in favor of men is also given

Slow light with integrated gain and large pulse delay

We demonstrate slow and stored light in Rb vapor with a combination of desirable features: minimal loss and distortion of the pulse shape, and large fractional delay (> 10). This behavior is enabled by: (i) a group index that can be controllably varied during light pulse propagation; and (ii) controllable gain integrated into the medium to compensate for pulse loss. Any medium with the above two characteristics should be able to realize similarly high-performance slow light.Comment: 5 pages, 4 figures; abstract is shortened, some typo correcte

Prevention method of toric intraocular lens rotation after phacoemulsification of cataract using a standard capsule ring

At the same time, phacoemulsification of cataracts remains the most popular surgery. But the problem among phacosurgeons is the correction of existing corneal astigmatism. According to studies, about 30% of the world's population have corneal astigmatism with a strength of 0.75D and above, which leads to a decrease in visual acuity after phacoemulsification of cataracts in the absence of its correction.The most commonly used method to correct corneal astigmatism is the implantation of toric intraocular lenses (TIOL). The main condition for obtaining high visual acuity after TIOL implantation is the location of the astigmatic component of the artificial lens in accordance with the strong meridian of the cornea. The aim of this study was to evaluate the effectiveness of the proposed method of preventing the toric intraocular lens rotation after phacoemulsification of cataracts in the eyes with corneal astigmatism by implantation of a standart capsule ring.Material and methods. The article presents the results of a comprehensive examination of 43 patients (59 eyes) who underwent surgery by phacoemulsification of cataracts with implantation of toric IOL to correct concomitant corneal astigmatism. Corneal astigmatism according to keratometry ranged from 0.5D to 4.25D (average 1.96 ± 0.1 D). Patients were divided into 2 groups. The first group consisted of 26 patients (31 eyes). Patients in this group underwent phacoemulsification with toric IOL implantation according to standard techniques without the use of techniques that prevent rotation of the artificial lens in the postoperative period. The second group included 18 patients (28 eyes) who were operated on according to our proposed prevention method of TIOL rotation. As a result of the study, it was found that rotation of TIOL was detected 6 months after surgery in the I group without the use of developed method in 22 eyes (70.9%), in the II group, where the capsule ring was implanted, rotation occurred in 12 eyes (42.85%). In the II group in all cases, the deviation of the TIOL axis did not exceed 6 degrees. The proposed method of prevention of rotation of TIOL allows to increase the efficiency of phacoemulsification of cataracts.Conclusions. Developed a method of preventing the rotation of the toric intraocular lens using a standard capsule ring, which is implanted and located on top of the haptic support elements of the artificial lens can increase the efficiency of phacoemulsification of cataracts in the eyes with corneal astigmatism, contributes to the rotational stability of the toric lens and provides long-term results of visual functions, reduces the need for repeated surgery due to reposition of the rotated lens and can be recommended for implementation in the practice of ophthalmic surgeons.The use of implantation of a standard capsule ring according to the proposed in this study method prevents the rotation of the toric intraocular lens by more than 6 degrees in all cases, which does not significantly reduce visual acuity and does not require reposition of the artificial lens. This method of preventing rotation of the toric intraocular lens allows to achieve visual acuity of 0.7 and above in 85.6% of cases

Comparison of 87Rb N-resonances for D1 and D2 transitions

We report an experimental comparison of three-photon-absorption resonances (known as "N-resonances") for the D_1 and D_2 optical transitions of thermal 87Rb vapor. We find that the D_2 N-resonance has better contrast, a broader linewidth, and a more symmetric lineshape than the D_1 N-resonance. Taken together, these factors imply superior performance for frequency standards operating on alkali D_2 N-resonances, in contrast to coherent population trapping (CPT) resonances for which the D_2 transition provides poorer frequency standard performance than the D_1 transition.Comment: 3 pages, 4 figure