Spectroscopic and lasing characteristics of an Yb-doped silica rod fabricated by the vapor-phase axial deposition technology

Spectroscopic and lasing characteristics of the ytterbium (Yb)-doped silica-based rod fabricated by the vapor-phase axial deposition technology is reported. Using a high-quality Yb-doped silica (Yb:silica) rod with a diameter of 1.5 mm, we calculated the absorption and emission cross sections based on measurement of the absorption spectrum, resulting in a maximum absorption cross section of 3.84 × 10 ⁻¹⁹ cm ² at 978 nm and a maximum emission cross section of 4.23 × 10 ⁻¹⁹ cm ² at 980 nm. In addition, the fluorescent lifetime was measured to be 974 μs. We applied the Yb:silica rod to a laser amplifier, yielding 72 W of amplified continuous-wave output at 1030 nm with a slope efficiency of 28%. Prospects of power scaling along with achievement of good beam quality are discussed.