Ya. K. Skasyrskii

Luminescence of ZnO nanorods grown by chemical vapor deposition on (111) Si substrates

ZnO nanorods have been grown on (111) Si substrates by chemical vapor deposition in a horizontal reactor, with no catalyst. The nanorods grown far from the outlet end of the reactor are larger in size, have a higher structural perfection, and exhibit more efficient room-temperature edge luminescence in comparison with the nanorods grown at the outlet end. The low-temperature cathodoluminescence spectrum of the nanorods also depends on their position in the reactor during growth, which is interpreted in terms of the density of native defects. The nanorods exhibit room-temperature stimulated emission in the excitonic spectral region.

Passive Q-switching of the diode-pumped Er:YAG laser cavity with the Q-switch based on the Fe2+:ZnSe crystal

Repetitive-pulse generation of the diode-pumped Er:YAG laser (λ = 2.94 µm) in the free mode and in the mode of cavity passive Q-switching was achieved using a Q-switch based on the Fe2+:ZnSe crystal. When using pump pulses 3 ms long, the pulse-average output power of the Er:YAG laser in the free generation mode was 0.5W. In the passive Q-switching mode, giant pulses 180 ns long with an energy of 3 µJ were obtained.

Luminescent properties of vertically aligned ZnO nanorod arrays grown on (100) Si substrates

The effect of the dimensions of zinc oxide nanorods on their cathodoluminescence (CL) has been studied in the visible through UV spectral region. The results indicate that hexagonally faceted columnar nanordos grown on (100) Si substrates are aligned almost vertically. The chemistry of point defects in the nanorods is shown to depend on their position in the reactor during growth. The low-temperature CL spectra of the nanorods show peaks due to bound excitons and electron recombination through the nitrogen acceptor level. Electron microscopy results show that the ZnO nanocrystals are highly uniform in shape and size and that these parameters depend on the chemical vapor deposition conditions.

Efficient and compact pulse-periodic Cr2+:CdSe laser emitting in the wavelength regions of 2.8 and 3.3 µm

Pulse-periodic lasing at wavelengths of 2.8 and 3.3 µm is obtained in the Cr2+:CdSe single-crystal laser. In the region of 2.8 µm, the pumping conversion is 28% (more than 50% of the absorbed energy). In the region of 3.3 µm, lasing is achieved at several tunable narrow lines appropriate for using in remote lidars. The pumping conversion in this spectral region is more than 17% (more than 30% of absorbed energy).

CW Cr2+:CdSe laser pumped by semiconductor disk laser

An output power of 0.85 W with a differential efficiency with respect to absorbed pump power of 55.4% is achieved for a Cr2+:CdSe laser with a wavelength of 2.6 µm under optical pumping with a semiconductor disk laser with a wavelength of 1.98 µm.

A continuous-wave Fe{sup 2+}:ZnSe laser

A continuous-wave oscillation is obtained for the first time in a Fe{sup 2+}:ZnSe laser. The laser wavelength was in the range from 4.04 to 4.08 {mu}m. A liquid-nitrogen-cooled active element was pumped by a Cr{sup 2+}:CdSe laser at 2.97 {mu}m. The maximum output power of the laser was 160 mW with the 56% slope efficiency. The minimum absorbed pump power threshold was 18 mW. The intrinsic losses in the Fe{sup 2+}:ZnSe crystal did not exceed 0.024 cm{sup -1} during lasing. (lasers. amplifiers)