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

50-component Theory for Spin 2 Particle, Plane Wave Solutions, Massive and Massless Cases

It is known a 50-component theory for a spin 2 particle with the anomalous magnetic moment, invariant under the Lorentz group and based on the use of symmetric 2-nd rank tensor and a 3-rd rank tensor symmetric in two indices. Their symmetries are similar to these of the metric tensor and Christoffel symbols of General relativity. By eliminating the 3-rd rank tensor we derive a system of 2-nd order 10 equations for symmetric tensor. This system is studied for plane wave solutions. In massive case, we have found 5 independent solutions. Separately, we have examined the case of a massless field. There are found 6 independent solutions, 4 special combinations of them are identified with the gauge solutions in accordance with Pauli - Fierz approach. Finally we have found two solutions which do not contain any gauge components