Laser performance and spectroscopic analysis of optically written channel waveguides in neodymium-doped gallium lanthanum sulphide glass

We present a spectroscopic analysis and laser characterization of optically written waveguides in neodymium-doped gallium lanthanum sulphide (Nd<sup>3+</sup>-Ga:La:S) chalcogenide glass. Uniform channel waveguides were fabricated in Nd<sup>3+</sup>-Ga:La:S by exposure to radi...

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Bibliographic Details
Main Authors: Mairaj, A.K (Author), Chardon, A.M (Author), Shepherd, D.P (Author), Hewak, D.W (Author)
Format: Article
Language:English
Published: 2002.
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Summary:We present a spectroscopic analysis and laser characterization of optically written waveguides in neodymium-doped gallium lanthanum sulphide (Nd<sup>3+</sup>-Ga:La:S) chalcogenide glass. Uniform channel waveguides were fabricated in Nd<sup>3+</sup>-Ga:La:S by exposure to radiation from a focused uv-laser beam (λ = 244nm), producing a refractive index change Δ.n ~ +10<sup>-3</sup>. The observed laser performance and fluorescence decay were in good agreement with values calculated from a spectroscopic analysis of 85µs for the <sup>4</sup>F<sub>3/2</sub> lifetime and 5.9 x 10<sup>-20</sup>cm<sup>2</sup> for the emission cross-section at 1075nm. Low threshold laser operation with emission at 1075nm and a slope efficiency of 17% is demonstrated. The active device is spatially single-mode and exhibits up to 8.6mW output power and propagation losses of <0.5 dB cm<sup>-1</sup>. Waveguide fabrication, photoinduced effects and optical characterization in terms of spectroscopy, laser performance and device attenuation are discussed.