Dynamics of Er3+:YAG thermal radiation spectra near solid-melt interface at single crystal fiber growth process

• Published in: Journal of crystal growth 2019-01, Vol.506, p.165-170
• Main Authors: Bufetova, G.A., Rusanov, S.Ya, Seregin, V.F., Pyrkov, Yu.N., Tsvetkov, V.B.
• Format: Article
• Language: English
• Subjects: A1. Characterization; A1. Interfaces; A1. Optical absorption; A1. Radiation; A2. Laser heated pedestal growth; B1. Er:YAG
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2018.10.043

[Display omitted] •Er3+:YAG thermal radiation spectra evolution in growth zone were observed at LHPG.•Er3+:YAG melt radiates as a black body in several spectral bands in visible range.•Melt temperature ∼2620 K was determined using thermal radiation saturation in bands.•Emissivity spectral profile of Er3+:YAG was obtained for ∼1 mm melt thickness.•Er3+:YAG melt absorption coefficient was estimated from emissivity spectral profile. The evolution of the Er3+:YAG thermal radiation spectra at heating up to the melting point was investigated in the visible range when growing a crystal fiber by the Laser-Heated Pedestal Growth (LHPG) method. The Er3+:YAG melt of about 1 mm thickness radiates like a black body in several spectral bands sometimes different from the crystal absorption lines. The real melt temperature in the middle of the growth zone was estimated as 2620 ± 15 K. The spectral profile of Er3+:YAG emissivity in the visible range for a melt layer of about L ≈ 1 mm at 2620 K is shown in the Figure.