Reference Voltage Supply Source with Expanded Operating Temperature Range

The circuit of reference voltage surface with enhanced operation temperature range was developed. The operating temperature range was enlarged by a current source connected to output terminal of the regular output of LM4050 voltage regulator

Passive mode locking of a Tm,Ho:KY(WO4)(2) laser around 2 μm

We report the first demonstration, to our knowledge, of passive mode locking in a Tm3+, Ho3+-codoped KYWO42 laser operating in the 2000-2060 nm spectral region. An InGaAsSb-based quantum well semiconductor saturable absorber mirror is used for the initiation and stabilization of the ultrashort pulse generation. Pulses as short as 3.3 ps were generated at 2057 nm with average output powers up to 315 mW at a pulse repetition frequency of 132 MHz for 1.15 W of absorbed pump power at 802 nm from a Ti:sapphire laser

Spin 3/2 Particle in the Presence of Magnetic Field: Tetrad Formalism and Fedorov-Gronskiy Method

A spin 3/2 particle is considered in the presence of an external uniform magnetic field. The covariant representation of the Rarita – Schwinger first order equation for vector-bispinor wave function in cylindrical coordinates and tetrad is used. On searching solutions we diagonalize the operators of the energy, the third projection of the linear momentum, and the third projection of the total angular momentum, as a result we derive the system of 16 first order differential equations in the variable r. To resolve this system of equations we apply the Fedorov–Gronskiy method which is based on the use of the projective operators related to 16-dimensional generator J12 for vector-bispinor. Within this approach we decompose the complete wave function into the sum of four projective constituents, each of them is determined by only one corresponding function fi(r), i = 1, 2, 3, 4. For these four basic functions we have constructed the exact solutions in terms of confluent hypergeometric functions. In accordance with the general Fedorov–Gronskiy approach we transform the differential first order system of 16 equations into algebraic homogenous system. From vanishing its determinant we derive and algebraic equation of the fourth order with respect to the squared energy, its solutions give possible values for the energy of the particle. In this way, we find 4 series of real-valued and physically interpretable energy spectra, all remaining ones provide us with complex-valued energies and they should be ignored (they are the so called anomalous solutions)

Spin 2 Particle with Anomalous Magnetic Moment in Presence of Uniform Magnetic Field, Exact Solutions and Energy Spectra

The 50-component matrix equation for spin 2 particle with anomalous magnetic moment is studied in presence of external magnetic field. The matrix tetrad based form of equation in the cylindrical coordinates is used. By diagonalizing the operators of energy, of the third projection of the total angular momentum and the third projection of the linear momentum wa derive the system of 50 differential equations of the first order in polar coordinate. In accordance with the method by Fedorov – Gronskiy based on the use of projective operators, we express all the 50 variables trough 7 different functions? equations for them reduce to the confluent hypergeometric functions. In the result, we obtain a 50-component system algebraic equations which should determine the structure of the total wave function. After eliminating the variables related to 40 components of the third rank tensor we derive the homogeneous algebraic system of 10 equations. It is solved, giving 5 independent solutions. There arise 5 different energy spectra as solutions of the 2-nd and the third order equations. They are found in analytical form and studied numerically

Безмассовое поле со спином 3/2: сферические решения и устранение калибровочных степеней свободы

Relativistic system for a vector-bispinior describing a massless spin 3/2 field is studied in the spherical coordi- nates of Minkowski space. Presentation of the equation with the use of the covariant Levi-Civita tensor exhibits existence of the gauge solutions in the form of the covariant 4-gradient of an arbitrary bispinor. Substitution for 16-component field func - tion is based on the use of Wigner functions, it assumes diagonalization of the operators of energy, square and third projection of the total angular momentum, and space reflection. We derive radial system for eight independent functions. General struc - ture of the spherical gauge solutions is specified, and it is demonstrated that the gauge radial functions satisfy the derived system. It is proved that the general system reduces to two couples of independent 2-nd order and nonhomogeneous differen - tial equations, their particular solutions may be found with the use of the gauge solutions. The corresponding homogeneous equations have one the same form, they have three regular singularities and one irregular of the rank 2. Frobenius types solu- tions for this equation have been constructed, and the structure of the involved power series with 4-term recurrent relations sre studied. Six remaining radial functions may be straightforwardly found by means of the simple algebraic relations. Thus, we have constructed two types of solutions with opposite parities which do not contain gauge constituents