Effect of Si-induced defects on 1 µm absorption losses in laser-grade YAG ceramics

Gaumé, Romain; He, Yu; Markosyan, A. S.; Byer, Robert L.

doi:10.1063/1.4709756

Cited by 26 publications

(15 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It thus appears that SiO 2 dopant does not inhibit the Cr ion from shifting valence state from 3+ to 4+ when added in combination with CaO, but it does prohibit the transformation of unstable octahedral Cr 4+ to tetrahedral Cr 4+ by generating local distortions in the YAG lattice. Gaume et al observed similar behavior with Si doping YAG and proposed that Si impurities can stabilize electrons near oxygen vacancies and form bound polarons. It seems likely that the same phenomenon is active in this study.…”

Section: Resultsmentioning

confidence: 74%

Assessment of conversion efficiency of Cr⁴⁺ ions by aliovalent cation additives in Cr:YAG ceramic for edge cladding

Chen

Lù

et al. 2018

J Am Ceram Soc

View full text Add to dashboard Cite

0.25at.% Cr:YAG ceramics were successfully fabricated as the edge cladding of Yb:YAG transparent ceramic slabs through vacuum sintering of co‐precipitated powders, using oxide additives to introduce different cations. The effects of various cation additives (Si4+, Ca2+, and Si4+ + Ca2+) on the conversion efficiency of Cr4+ ions and optical characteristics of the Cr:YAG edge cladding were investigated. Measurements of the absorption spectra of the Cr:YAG ceramics without any additives revealed 2 absorption bands centered at 430 nm and 600 nm, which imparted the sample with a green color. The introduction of only Si4+‐bearing additive did not promote the transition of Cr ions from the 3+ to 4+ state. Theoretical analysis and experimentation revealed that the addition of CaO not only enhanced the microstructure and improved the transmittance of the Cr:YAG ceramic, but also introduced vacancies that assisted in the formation of Cr4+ ions. It was determined that CaO has the same effect on the conversion efficiency of Cr4+ ions whether it is added as a single additive or in combination with SiO2. The underlying mechanisms by which these aliovalent cation additives influence the formation of Cr4+ ions and affect optical properties are discussed in detail. High quality composite ceramics with Yb:YAG transparent ceramic slabs and dark brown‐colored Cr4+: YAG ceramic edge cladding were achieved through the addition of 0.05 wt.% CaO to the edge cladding, with no interfacial effects between the 2 regions being observed.

show abstract

Section: Resultsmentioning

confidence: 74%

Assessment of conversion efficiency of Cr⁴⁺ ions by aliovalent cation additives in Cr:YAG ceramic for edge cladding

Chen

Lù

et al. 2018

J Am Ceram Soc

View full text Add to dashboard Cite

show abstract

“…They determined Si doping YAG at levels below the solubility limit could not volatilized, meanwhile would result in the equilibrium segregation of Si to the grain boundaries. Additionally, the SiO 2 additives easily produce the optical absorption around 1 µm and lower the optical quality of Yb:YAG ceramics, even though for the low concentration of SiO 2 additives . Hence the microstructure evolution of Yb:YAG ceramics without the use of sintering additives were explored in the present study.…”

Section: Resultsmentioning

confidence: 99%

Fabrication and microstructure development of Yb:YAG transparent ceramics from co‐precipitated powders without additives

Chen

Wei

et al. 2019

J Am Ceram Soc

View full text Add to dashboard Cite

Sintering additives are generally considered to be important for improving densification in fabrication of transparent ceramics. However, the sintering aids as impurities doped in the laser materials would decrease the laser output power and produce additional heat during laser operation. In this work, Yb:YAG ceramics were vacuum‐sintered without additives at different temperatures for various soaking time through using ball‐milled powders synthesized by co‐precipitation route. The densification behavior and grain growth kinetics of Yb:YAG ceramics were systematically investigated through densification curves and microstructural characterizations. It was determined that the densification in the 1500°C‐1600°C temperature range was controlled by a grain‐boundary diffusion. It is revealed that the volume diffusion is the main mechanism controlling the grain growth between 1600°C and 1750°C. Although SiO2 additives can promote densification during low‐temperature sintering, the optical transmittance of Yb:YAG ceramic with no additives, sintered at 1800°C for 15 hours, reaches a maximum of 83.4% at 1064 nm, very close to the measured transmittance value of Yb:YAG single crystal. The optical attenuation loss was measured at 1064 nm in Yb:YAG transparent ceramic, to be 0.0035 cm−1, a value close to that observed for single crystals.

show abstract

“…Generally, SiO 2 is used as sintering aids to sinter YAG ceramics. When Si 4+ is substituted Al 3+ site, cation defect is generated and due to this lattice defect in the material, a small amount of optical absorption occurs around 1 μm wavelength regions, which causes the generation of heat during laser operation . In addition to SiO 2 sintering aids, other sintering aids such as CaO, MgO, and fluorites are also reported that they are useful to make fully transparent ceramics.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Yb:YAG Ceramics Without Sintering Additives and their Performance

Ikesue¹,

Aung²

2016

J. Am. Ceram. Soc.

View full text Add to dashboard Cite

High‐quality 10%Yb:YAG ceramics was successfully synthesized without sintering additives such as SiO2 for the first time. Optical scattering loss of the Yb:YAG ceramics was 0.1%/cm and its transmitted wavefront distortion was λ/19.5 (t = 4.7 mm), which was very comparable to single crystal laser materials. Laser performance of thin disk made of this material (φ11 × t0.15 mm) was 74.1% of slope efficiency (optical‐to‐optical conversion efficiency: 68.1%) and the maximum output power reached 1.8 kW. Synthesis of high‐purity and high‐quality YAG ceramics without using sintering additives was demonstrated for the first time to our knowledge and we can discuss the technological meaning of high‐purity materials for the future.

show abstract

Effect of Si-induced defects on 1 µm absorption losses in laser-grade YAG ceramics

Cited by 26 publications

References 34 publications

Assessment of conversion efficiency of Cr⁴⁺ ions by aliovalent cation additives in Cr:YAG ceramic for edge cladding

Assessment of conversion efficiency of Cr⁴⁺ ions by aliovalent cation additives in Cr:YAG ceramic for edge cladding

Fabrication and microstructure development of Yb:YAG transparent ceramics from co‐precipitated powders without additives

Synthesis of Yb:YAG Ceramics Without Sintering Additives and their Performance

Contact Info

Product

Resources

About

Effect of Si-induced defects on 1 µm absorption losses in laser-grade YAG ceramics

Cited by 26 publications

References 34 publications

Assessment of conversion efficiency of Cr4+ ions by aliovalent cation additives in Cr:YAG ceramic for edge cladding

Assessment of conversion efficiency of Cr4+ ions by aliovalent cation additives in Cr:YAG ceramic for edge cladding

Fabrication and microstructure development of Yb:YAG transparent ceramics from co‐precipitated powders without additives

Synthesis of Yb:YAG Ceramics Without Sintering Additives and their Performance

Contact Info

Product

Resources

About

Assessment of conversion efficiency of Cr⁴⁺ ions by aliovalent cation additives in Cr:YAG ceramic for edge cladding

Assessment of conversion efficiency of Cr⁴⁺ ions by aliovalent cation additives in Cr:YAG ceramic for edge cladding