Spectral, luminescence, and lasing properties of a yttrium scandium gallium garnet crystal activated with chromium and erbium

Abstract

Using the method of weighted residuals, a detailed numerical study is made of the neutronics of spherical cold neutron sources composed of liquid hydrogen and liquid deuterium in reactor moderators of light water, heavy water and graphite, Particular attention is paid to the physical effects at the cold source boundary. The computations allow a number of conclusions to be made on the best designs of spherical cold source configurations. It is found that for small spherical sources there is little difference in neutron gain using either normal-hydrogen or para-hydrogen, and that the largest gains are obtainable from large deuterium-filled sources.

Thermal radiation of Er doped dielectric crystals: Probing the range of applicability of the Kirchhoff’s law

“…Co-doping the crystals with Cr 3+ ions, which have strong broadband absorption in the visible part of the spectrum, as in e.g . yttrium scandium gallium garnet (Y 3 Sc 2 Ga 3 O 12 ) doped with Er and Cr 41 , 43 , should improve absorption of solar radiation significantly. Thermal radiation band in the infrared range of the spectrum should be narrow.…”

“…3 ), and high melting temperature (1965 °C for Er:Y 3 Al 5 O 12 ) 40 – 42 . Even higher absorption efficiency can be achieved in Er 3+ doped crystals, such as yttrium scandium gallium garnet (Y 3 Sc 2 Ga 3 O 12 or YSGG), co-doped by Cr 3+ ions 41 , 43 . Other rare-earth ions of potential importance to thermophotovoltaics have strong absorption and emission bands at ~1.8 μm (Tm 3+ ), ~2.0 μm (Ho 3+ ) and ~3.4 μm (Dy 3+ ) 40 , 41 , 44 .…”

Optical spectroscopy of Er:YSGG laser crystal

“…Therefore, the lattice structure of Er:YSGG should be equivalent to YSGG. Furthermore, as the Er 3 + ions doped into YSGG host, the scandium ions which are of small size would hinder penetration of the Er 3 + ions to the octahedral positions [8], then some dodecahedral sites of the Y 3 + ions are replaced by the Er 3 + ions based on their identical valence (+ 3) and similar radius[R (Er 3 + ) ¼88 pm, R (Y 3 + )¼89 pm]. The lattice parameters of Er:YSGG measured are a ¼b¼c ¼12.464070.0065Å, a¼b¼g¼901.…”

Dynamics of a flashlamp pumped 270 μm emission Cr:Er:YSGG laser with an infrared-quartz FTIR shutter

“…In recent years, research on erbium lasers has attracted a great deal of attention in relation to medical applications [1][2][3][4][5][6]. Cr 3+ -codoped Er 3+ on YSGG crystal is an important IR laser material [7][8][9]. In particular, the giant short pulse of 2.70 m wavelength obtained with the Cr:Er:YSGG laser offers several advantages: high transmittance in conventional optic fibers, small thermal damage during the ablation of tissues, and proper penetration depth in tissue water.…”