Temperature characteristics of green upconversion fluorescence of Er3+-doped SrGdGa3O7 crystal

Characteristics of 980-nm-upconverted green 530 and 550 nm fluorescence of Er3+-doped SrGdGa3O7 single crystal have been studied for temperature sensing purposes. A simple experimental setup has been developed that consists of a laser diode, two interference filters, two Si-photocells and two multimeters, without use of monochromator or focusing lens for fluorescence collection. The study shows that the Er:SrGdGa3O7 crystal displays stronger green emission intensity and hence better signal-to-noise ratio, as well as higher temperature sensitivity. The results of temperature characteristics are consistent with those obtained from the experiments repeated using a spectrometer. It is concluded that the Er:SrGdGa3O7 crystal is a promising substrate material for both lasers and temperature sensing.306