Study On Spectral Properties Of Rare Earth Doped Silicate Glass

In the field of special optical glass,rare earth doped glass materials has been widely used in the fields of optics transmission and conversion,optical storage and photoelectric display due to its special optical effects in visible and near-infrared regions.The application of inorganic oxide glass is extremely broadened in rare earth doped optical materials,especially in silicate glass,borate glass,phosphate glass,bismuth silicate glass,etc.Among them,silicate glass has a series of advantages,such as its good chemical stability,high thermal stability,easy thermal processing,high transmittance in the UV-visible region and relatively low production costs.Therefore,it attracts a lot of concern.In this paper,the research progress and the issues encountered in recent study of rare earth doped silicate glasses are reviewed and summarized.Then,the future research direction and emphasizes are forecasted.Secondly,based on the multi-level characteristics of rare earth ions,Yb3+/Tm3+/Ho3+/Ce3+/Sm3+ rare earth single-doped,double-doped and triple-doped silicate glasses are prepared for its demands on high efficiency,environmental protection and low cost practical requirements of light conversion devices.The optical properties of rare earth doped silicate glasses,such as fluorescence spectrum,reflection spectrum,transmission spectrum and refractive index,are systematically studied.Combined with up-conversion luminescence,down-conversion luminescence,the optimal control law of the absorption properties is summarized.Also,the rare earth doped silicate glasses are investigated in stealth application.All the results are listed in details:1.The up-conversion luminescence properties of Yb3+/Tm3+/Ho3+ doped silicate glasses are studied.Based on the energy level diagram of rare earth ions and its transition theory,the energy transfer mechanism between rare earth ions is analyzed.While the optimal ratio of Tm3+/Ho3+ ion is clarified.In the case of Yb3+/Tm3+ and Yb3+/Ho3+co-doped silicate glasses,the compliance relationship between up-conversion luminescence intensity and excitation power was analyzed under 980 nm laser pumping.The result shows that the up-conversion luminescence in Yb3+/Tm3+ and Yb3+/Ho3+ co-doped silicate glasses is a three-photon process and the best concentration of Tm3+ and Ho3+ are 0.3 mol% and 0.4mol%,respectively.In Yb3+/Tm3+/Ho3+ co-doped silicate glasses,the pumping energy were absorbed by Yb3+ ions and then transferred to Tm3+/Ho3+,along with a cross-relaxation process between Ho3+ and Tm3+.Finally,it comes out a decreased blue light emitted by Tm3+ ions and an enhanced red and green light emitted by Ho3+ ions.2.The down-conversion luminescence properties of Ce3+/Tm3+/Sm3+ doped silicate glasses are studied.The luminescence mechanism of Ce3+/Tm3+/Sm3+ tri-doped silicate glasses are discussed on the basis of the energy level diagram of rare earth ions and its transition theory.The luminescence intensity are strongly dependent on the dopingconcentration of Ce3+/Tm3+/Sm3+ ions.The fluorescence spectra of Ce3+-Ce3+/Tm3+,Ce3+-Ce3+/Sm3+ and Tm3+-Tm3+/Sm3+ co-doped silicate glasses were compared and analyzed.Under excitation of 342 nm,Ce3+ doped silicate glasses have a strong excitation peak at 385 nm with a FWHM of 48 nm and the optimal concentration Ce3+ ions is 0.2mol%.By 357 nm excitation,the optimal concentration of Tm3+ ions in Ce3+/Tm3+double-doped silicate glass is 0.4 mol%.While under 400 nm excitation,the optimal concentration of Sm3+ ions in Ce3+/Tm3+/Sm3+ triple-doped silicate glass is 1.1 mol%.The Ce3+/Tm3+/Sm3+ doped silicate glass has achieved the goal that a designed and prepared rare earth doped glass which can absorb near-ultraviolet light(280-400 nrn)and emit blue-violet light(400-500 nm)and red-orange light(590-680 nm).3.The spectral properties of rare earth doped silicate glasses composite applied in stealth technology are studied.According to the needs laser stealth composites,an infrared laser stealth composites working on 1064 nm,1535nm and 1550 nm are prepared.The main absorption elements,matrix and curing agent are Sm3+/Ce3+ ions,silicate glasses and polyurethane varnish,respectively.The reflection spectra of Sm3+ doped silicate glass composites are discussed in Sm3+ ions concentration,particle size,and the content of glass powder.When the concentration of Sm3+ ions is 40 mol%,the transmittance at 400 nm of this silicate glass powder is 4.2%,at the same time transmittance and reflectivity at 1064 nm are 1% and 3.55%,respectively.When the glass particle size is larger than 110 ?m and the mixing ratio is 1:1,the reflectivity at 1064 nm,1535 nm and 1550 nm are 6.85%,7.28%and 8.45%,correspondingly,which realized the low reflectivity in multi-wavelength.It indicates that the Sm3+-doped silicate glass is a potential candidate for stealth and anti-stealth technology in laser detection.