Study On Luminescence Properties Of Gd³⁺ Ions Doped Up-Conversion Micron Crystal

In recent years,due to the rapid development of high-density optical storage,lithography,submarine communications and medical fields,the demand for short-wavelength Diode Pumped solid state lasers has become more and more urgent.The rare earth ion doped up-conversion material as a core material which can simply realize the short wavelength Diode Pumped solid state laser is favored by a large number of researchers.Nowadays,Diode Pumped solid state laser in the visible light band has been successfully developed,but how to expand the application range of up-conversion lasers to obtain up-conversion laser in the ultraviolet band has become a common issue for researchers.As an important part of short-wavelength all-solid-state lasers,finding a new and efficient UV up-conversion material has become a common goal for them.The first excited state ⁶P_7/2of Gd³⁺ion is located in the ultraviolet region.This special energy level structure makes its up-conversion emission become very difficult.So far,only a few studies have reported the up-conversion emission of Gd³⁺ion,and most of them used green laser?546 nm?as a pump light source,but these luminous effects were not very satisfactory.The spacing between energy level of Er³⁺,Tm³⁺and Ho³⁺ions can match the 980 nm laser well,and have a rich energy level structure,which can emit up-conversion emission covering near infrared to ultraviolet.Therefore,it can well act as a sensitizer to excite Gd³⁺ion.However,studies on Er³⁺,Tm³⁺and Ho³⁺ions as sensitizers are rare.In this paper,the hexagonal?-Na YF₄ with lower phonon energy and better luminous efficiency was used as the matrix material to study the up-conversion emission of the sample under 980 nm laser excitation.The results are as follows:Na YF₄:Gd³⁺/Yb³⁺/Er³⁺,Na YF₄:Gd³⁺/Yb³⁺/Tm³⁺and Na YF₄:Gd³⁺/Yb³⁺/Ho³⁺micron crystals were synthesized by hydrothermal method,and these groups of samples were characterized and tested.Under the excitation of 980 nm laser,ultraviolet up-conversion emission from Gd³⁺ions were observed.When doped with Gd³⁺ions,the up-conversion emission of the samples in the ultraviolet band is enhanced.By analyzing the up-conversion spectra at different doping concentrations proves that the up-conversion emission of Gd³⁺ions derived from the sensitization of Er³⁺,Tm³⁺and Ho³⁺.After analyzing the up-conversion spectra at different doping concentrations proves that the up-conversion emission of Gd³⁺ions derived from the sensitization of Er³⁺,Tm³⁺and Ho³⁺.