Optical Bistability under Nonresonant Excitation in Spinor Polariton Condensates.

We realize bistability in the spinor of polariton condensates under nonresonant optical excitation and in the absence of biasing external fields. Numerical modeling of the system using the Ginzburg-Landau equation with an internal Josephson coupling between the two spin components of the condensate qualitatively describes the experimental observations. We demonstrate that polariton spin bistability strongly depends on the condensate's overlap with the exciton reservoir by tuning the excitation geometry and sample temperature. We obtain noncollapsing bistability hysteresis loops for a record range of sweep times, [10 µs, 1 s], offering a promising route to spin switches and spin memory elements.

[Development of an algorithm for spatial distribution of the radiation intensity from photometric therapeutic devices]. / Razrabotka algoritma raschet prostranstvennogo raspredeleniia intensivnosti izlucheniia fotomatrichnykh terapevticheskikh apparatov.

An algorithm for calculating the spatial distribution of radiation intensity from type-transparency matrix therapeutical apparatuses based on superbright light-emitting diodes is considered. The method developed takes into account the geometric and topological features of both radiation sources themselves and irradiated surfaces. The algorithm proposed is important in solving the problems of dosimetry of light therapeutical apparatuses already used in medical practice and those under design.