The amplitude fluctuations in a single-mode laser for the case of regular pumping when the atoms ... more The amplitude fluctuations in a single-mode laser for the case of regular pumping when the atoms are injected in the cavity at fixed, unfluctuating rate are discussed. The dressed atom approach is employed. A comparison is made of such pumping scheme with the conventional one, when the number of active atoms is fixed. The results of the present work agree
ICONO '95: Fundamentals of Laser-Matter Interaction, 1996
ABSTRACT A dielectric microsphere possesses natural modes of oscillation at characteristic freque... more ABSTRACT A dielectric microsphere possesses natural modes of oscillation at characteristic frequencies, corresponding to specific size to wavelength ratios. These structure resonances are known to cause extremely large field intensities and have extremely high quality. We investigate here systematically the characteristic equation, defining the natural frequencies, as a function of the change in the asymptotic behavior of spherical Bessel functions which reveals the fact that there exists resonances with very narrow linewidth. This characteristic has very important implications to nonlinear optics.
The conventional way of studying laser noise assumes analytic solution of the quantum problem for... more The conventional way of studying laser noise assumes analytic solution of the quantum problem for the laser field coupled to the active medium. A number of the laser schemes have been discussed, and predictions for noise reduction and for the squeezed state of field have been made.1 On the basis of first principies of the quantum mechanies, the conventional approach exhibits the relatively rare situation in which the quantum equations admit compact analytic solution. At the same time, the difficulty in interpreting the results seems to be unresolved. Specifically, it is very difficult lo determine the relative contribution of each physical source of noise to the final fluctuation result.
Autodyne lidar with CO2-laser is a good system for remote measurements of environmental gases 1 a... more Autodyne lidar with CO2-laser is a good system for remote measurements of environmental gases 1 as a number of them have absorption bands in spectral region 9-11 km. In this report we present an analytical approach for calculation of the parameters of a parametric autodyne lidar for environmental DIAL applications. This approach allows one to express analytically the parameters of the atmosphere, such as the absorption coefficient and the distance to remote target, through experimentally measured values. A model of parametric autodyne lidar based on two level laser scheme has been considered. The aim is to derive analytical dependencies of lidar field on parameters of the atmosphere. Two nonlinear differential equations for laser field amplitude at resonator mirrors are derived. Using reflectivity of the remote mirror as a small parameter (it can reach 10i 9 in field experiments) a perturbation theory has been built, which allows one to reduce nonlinear lidar equations to a couple o...
Technical Digest. Summaries of Papers Presented at the International Quantum Electronics Conference. Conference Edition. 1998 Technical Digest Series, Vol.7 (IEEE Cat. No.98CH36236), 1998
The behavior of a laser intensity as a function of a pump rate is studied. We consider a three-le... more The behavior of a laser intensity as a function of a pump rate is studied. We consider a three-level lasing scheme with two different types of pumping. In the first case, the lower lasing level is depleted to the ground state, and then the pumping is used to excite the atom from the ground state to the upper lasing level. In the second case the pumping is used to excite the atom directly from the lower lasing level to one of the excited states, which is then depleted to the upper lasing level. We refer these two types of pumping as type 1 and type 2, respectively. It is shown that although these two schemes are equivalent mathematically, i.e., they are formally described by the same set of equations, physically their dynamical properties are completely different. It is noted that the pumping of the type 1 does not affect either of lasing levels directly, whereas the pumping of the type 2 does connect the lower lasing level with one of the excited states. It is this difference of the two ways of pumping which is responsible for the crucial difference in the dynamic behavior of the lasing schemes of types 1 and 2
Optica Acta: International Journal of Optics, 1983
The present paper considers a model of a single-mode laser based on two-level atoms having transl... more The present paper considers a model of a single-mode laser based on two-level atoms having translational degrees of freedom. Correlation of the field and the atomic motion due to the recoil effect is taken into account. The self-consistent theory describing dynamic properties of the system is performed on the basis of semiclassical approximation. It is shown that due to the
We suggest an approach to study hierarchy, especially hidden one, of complex networks based on th... more We suggest an approach to study hierarchy, especially hidden one, of complex networks based on the analysis of their vulnerability. Two quantities are proposed as a measure of network hierarchy. The first one is the system vulnerability V. We show that being quite suitable for regular networks this characteristic does not allow one to estimate the hierarchy of large random networks. The second quantity is a relative variance h of the system vulnerability that allows us to characterize a "natural" hierarchy level of random networks. We find that hierarchical properties of random networks depend crucially on a ratio between the number of nodes and the number of edges. We note that any graph with a transitive isometry group action (i.e. an absolutely symmetric graph) is not hierarchical. Breaking such a symmetry leads to appearance of hierarchy.
It is shown that a three-level laser can become the first example of an optically active system t... more It is shown that a three-level laser can become the first example of an optically active system to generate a squeezed-field state.
The amplitude fluctuations in a single-mode laser for the case of regular pumping when the atoms ... more The amplitude fluctuations in a single-mode laser for the case of regular pumping when the atoms are injected in the cavity at fixed, unfluctuating rate are discussed. The dressed atom approach is employed. A comparison is made of such pumping scheme with the conventional one, when the number of active atoms is fixed. The results of the present work agree
ICONO '95: Fundamentals of Laser-Matter Interaction, 1996
ABSTRACT A dielectric microsphere possesses natural modes of oscillation at characteristic freque... more ABSTRACT A dielectric microsphere possesses natural modes of oscillation at characteristic frequencies, corresponding to specific size to wavelength ratios. These structure resonances are known to cause extremely large field intensities and have extremely high quality. We investigate here systematically the characteristic equation, defining the natural frequencies, as a function of the change in the asymptotic behavior of spherical Bessel functions which reveals the fact that there exists resonances with very narrow linewidth. This characteristic has very important implications to nonlinear optics.
The conventional way of studying laser noise assumes analytic solution of the quantum problem for... more The conventional way of studying laser noise assumes analytic solution of the quantum problem for the laser field coupled to the active medium. A number of the laser schemes have been discussed, and predictions for noise reduction and for the squeezed state of field have been made.1 On the basis of first principies of the quantum mechanies, the conventional approach exhibits the relatively rare situation in which the quantum equations admit compact analytic solution. At the same time, the difficulty in interpreting the results seems to be unresolved. Specifically, it is very difficult lo determine the relative contribution of each physical source of noise to the final fluctuation result.
Autodyne lidar with CO2-laser is a good system for remote measurements of environmental gases 1 a... more Autodyne lidar with CO2-laser is a good system for remote measurements of environmental gases 1 as a number of them have absorption bands in spectral region 9-11 km. In this report we present an analytical approach for calculation of the parameters of a parametric autodyne lidar for environmental DIAL applications. This approach allows one to express analytically the parameters of the atmosphere, such as the absorption coefficient and the distance to remote target, through experimentally measured values. A model of parametric autodyne lidar based on two level laser scheme has been considered. The aim is to derive analytical dependencies of lidar field on parameters of the atmosphere. Two nonlinear differential equations for laser field amplitude at resonator mirrors are derived. Using reflectivity of the remote mirror as a small parameter (it can reach 10i 9 in field experiments) a perturbation theory has been built, which allows one to reduce nonlinear lidar equations to a couple o...
Technical Digest. Summaries of Papers Presented at the International Quantum Electronics Conference. Conference Edition. 1998 Technical Digest Series, Vol.7 (IEEE Cat. No.98CH36236), 1998
The behavior of a laser intensity as a function of a pump rate is studied. We consider a three-le... more The behavior of a laser intensity as a function of a pump rate is studied. We consider a three-level lasing scheme with two different types of pumping. In the first case, the lower lasing level is depleted to the ground state, and then the pumping is used to excite the atom from the ground state to the upper lasing level. In the second case the pumping is used to excite the atom directly from the lower lasing level to one of the excited states, which is then depleted to the upper lasing level. We refer these two types of pumping as type 1 and type 2, respectively. It is shown that although these two schemes are equivalent mathematically, i.e., they are formally described by the same set of equations, physically their dynamical properties are completely different. It is noted that the pumping of the type 1 does not affect either of lasing levels directly, whereas the pumping of the type 2 does connect the lower lasing level with one of the excited states. It is this difference of the two ways of pumping which is responsible for the crucial difference in the dynamic behavior of the lasing schemes of types 1 and 2
Optica Acta: International Journal of Optics, 1983
The present paper considers a model of a single-mode laser based on two-level atoms having transl... more The present paper considers a model of a single-mode laser based on two-level atoms having translational degrees of freedom. Correlation of the field and the atomic motion due to the recoil effect is taken into account. The self-consistent theory describing dynamic properties of the system is performed on the basis of semiclassical approximation. It is shown that due to the
We suggest an approach to study hierarchy, especially hidden one, of complex networks based on th... more We suggest an approach to study hierarchy, especially hidden one, of complex networks based on the analysis of their vulnerability. Two quantities are proposed as a measure of network hierarchy. The first one is the system vulnerability V. We show that being quite suitable for regular networks this characteristic does not allow one to estimate the hierarchy of large random networks. The second quantity is a relative variance h of the system vulnerability that allows us to characterize a "natural" hierarchy level of random networks. We find that hierarchical properties of random networks depend crucially on a ratio between the number of nodes and the number of edges. We note that any graph with a transitive isometry group action (i.e. an absolutely symmetric graph) is not hierarchical. Breaking such a symmetry leads to appearance of hierarchy.
It is shown that a three-level laser can become the first example of an optically active system t... more It is shown that a three-level laser can become the first example of an optically active system to generate a squeezed-field state.
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Papers by G. Koganov