The main results 2009-2013

The main results for the period of 2009-2013:

  1. Features of the ytterbium generation spectra in the plates of Yb: YAG crystal and ytterbium-doped glass (with the activator concentrations of 20% and 10 %) at a high (1-5 GW / cm 2)  pumping intensity (20 ns laser pulses in LiF: F2 +color centers, focused on Ø250mkm site) have been registered:
    • Generation pulses of 1,0-1,06 microns with a spectral width of up to 200A in Yb: YAG and up to 500A in the ytterbium glass; a mechanism for broadband generation forming on the dynamic DFB – structure, appearing at the intensive acoustic waves propagation in the medium by a pumped stimulated Brillouin scattering, has been suggested;
    • Laser pulses of 1,03-1,05 m in the spectral lines with quasi-periodic structure of the spots along a gap height of spectrograph; a discovered structure is compared with the spatial oscillations period of thermoelastic stresses and a refractive index gradient, appearing in crystal and glass samples in the field of pumping energy release;
    • The obtained results indicate a diagnostics possibility for the small area optical medium with high gradients of temperature, pressure, and refractive index by the generation parameters of this area.
  2. A selection method of the scalar Laguerre-Gaussian modes of LGpm type (p- groove and m- azimuthal indices) in resonator parameters restructuring, comprising a lens with spherical aberration, has been proposed and implemented in experiments; the generation of a few tens of scalar LGpm modes of the lower and higher orders with different indices combinations (p = 0-12, m = 0-28) has been launched in Yb: YAG pumped semiconductor laser of the continuous mode with a capacity of up to 30 mW; a generation on modes with indices m = 7-28, p = 5-10 (m> p), as well as on several modes when p> m has been first obtained.
  3. A selection method of Laguerre-Gaussian vector modes when using a lens in the laser resonator with a spherical aberration and doubly refracting plate of uniaxial crystal has been proposed and tested in experiments; a generation of Laguerre-Gaussian vector modes of lower and higher orders with radial and azimuthal polarization with the number of rings from 1 to 10 has been launched in Yb: YAG pumped semiconductor laser of the continuous mode with a capacity of up to 60MW; some vector modes of the higher order have been obtained for the first time.