One of the promising active ions giving the possibility of laser radiation generation in 4 - 5 μm region is trivalent dysprosium in lead thiogallate crystal. On the basis of our previous Dy³⁺:PbGa₂S₄ laser study, this work is showing a several wavelengths generation possibility. The laser was working at the room temperature and it was in-band pumped by the Er:YLF laser radiation with the wavelength 1.73 μm. The investigated crystal Dy³⁺:PbGa₂S₄ was synthesized using Bridgman technique from the melt. Dimension of the sample was 16 mm long and 19 mm in diameter and the nominal Dy³⁺ ion concentration was ~ 0.7 at. %. The laser operation was tested with three resonator configurations. The first was the non-selective resonator with the length 41 mm. To perform the wavelength tuning, in the second case the MgF₂ Lyot filter was inserted under Brewster angle inside the resonator which length was 100 mm. In both these cases the laser resonator was formed by the incoupling flat dichroic mirror with low reflectivity at pumping wavelength (T = 90%@1.73 μm) and high reflectivity (R~100%) within the 3.5 - 4.5 μm spectral range, and by an out-coupling concave (r = 500 mm) mirror with reflectivity of 95 % or 98 % in the same region of wavelengths. For the third case the selective mirrors supporting the 3.0 - 4.0 μm spectral region were chosen. The generation possibility on three lines 4 μm, 4.3 μm, and 4.6 μm were found without continuous tuning between them.

Date Published: 15 February 2012
PDF: 7 pages
Proc. SPIE 8235, Solid State Lasers XXI: Technology and Devices, 82351X (15 February 2012);

Published in SPIE Proceedings Vol. 8235:
Solid State Lasers XXI: Technology and Devices
W. Andrew Clarkson; Ramesh K. Shori, Editor(s)