Abstract
This study investigates the temperature dependence of the normal emittance in 3-5, 5, 10.6 and 8-12 μm spectral range for LiNbO3 and LiF rods with both crystal and polycrystalline structures. According to the results, the normal emittance in the near-infrared spectra increases with increasing wavelength. The normal emittances at 10.6 and 8-12 μm are not only invariant with temperature, but also exceed 0.9. When the temperature increases, the normal emittances at 3-5 and 5 μm for the LiF single-crystal rod continuously increase regardless of the phase change from the solid state to the liquid state. Before the temperature reaches the Curie point, the normal emittances at 3-5 and 5 μm for the LiNbO3 single-crystal rod increase with increasing temperature. The normal emittances at 3-5 and 5 μm then decrease as the temperature further increases. A significant decrease in the normal emittance at 3-5 and 5 μm occurs when the emission is only from the melt. In addition, the magnitudes of the normal emittance at 3-5 and 5 μm are enhanced by the scattering effect due to the porous structure of the solid.
Original language | English |
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Pages (from-to) | 4070-4075 |
Number of pages | 6 |
Journal | Japanese Journal of Applied Physics |
Volume | 37 |
Issue number | 7 |
DOIs | |
State | Published - Jul 1998 |
Keywords
- Emittance
- Laser melting
- LiF
- LiNbO
- Single crystal