Temperature Sensing with Nd3+ Doped YAS Laser Microresonators

Yttria–alumina–silica (YAS) glass microspheres doped with Nd3+ ions were excited with a 532 nm continuous laser in order to study the dependency of the wavelength of the whispering gallery mode (WGM) peaks on the temperature of the sample. This was possible due to a previous calibration of the 808 nm and 890 nm emission bands of the Nd:YAS glass sample for different temperatures using the fluorescence intensity ratio (FIR) technique. A maximum sensitivity of 15 × 10−6 K−1 and a temperature resolution limit of 0.2 K were obtained for the microsphere sensor. Moreover, laser emission at 1064 nm was observed by continuous pumping at 532 nm, and a power threshold of 100 mW was determined. Upconversion emissions of Nd3+ were also studied by exciting the sample at 808 nm.

Enhancing the temperature sensitivity of Cr3+ emissions by modification of the host composition for fluorescent thermometry applications

The fluorescence intensity ratio (FIR) technique is widely adopted in thermometric phosphor materials, but the improvement of relative sensitivity is normally limited by the fixed energy gap between two thermally-couped...

The Enhancement of Upconversion Luminescence of Gd2O3:Yb,Er Nanoparticles by Ca2+ Codoping for Temperature Sensing at Room and High Temperatures

We prepared a series of Gd2O3:Yb,Er,Ca (3/1/[Formula: see text][Formula: see text]mol.%, [Formula: see text] represents the nominal concentration of Ca element including 0, 2, 3, 4, 5, 7, 10) upconversion nanoparticles (UCNPs) with regular morphology via a wet-chemical route. We observed a simultaneous enhancement of upconversion luminescence (UCL) emission of Gd2O3:Yb,Er after Ca[Formula: see text] ions were doped. When the doping level of Ca[Formula: see text] reaches its optimal concentrate at 5[Formula: see text]mol.%, the red and green emissions increased by 6.3 and 11 times, respectively. The potential application of Gd2O3:Yb,Er,Ca material as a noninvasion optical thermometry based on FIR technique was investigated. The sensing of temperature at both high and room temperatures was realized by choosing different parameters. The absolute temperature sensitivity ([Formula: see text]) of Gd2O3:Yb,Er nanoparticles at 293[Formula: see text]K reached 0.0875[Formula: see text]K[Formula: see text], whereas Gd2O3:Yb,Er, 5[Formula: see text]mol.%Ca was chosen as sensor of high temperature due to its considerable Sa of 0.0060[Formula: see text]K[Formula: see text] at 573[Formula: see text]K. The resultant UCNPs provided a new way for sensitive thermal detection at various target temperatures.

Highly reliable all-fiber temperature sensor based on the fluorescence intensity ratio (FIR) technique in Er3+/Yb3+ co-doped NaYF4 phosphors

A simple and feasible method was used to fabricate the optical temperature probe. A point all-fiber temperature sensor was built based on the up-conversion emission spectra of Er3+/Yb3+ co-doped NaYF4 phosphors.

Facile preparation of upconversion microfibers for efficient luminescence and distributed temperature measurement

The distributed temperature at different positions of Er3+-doped microfibers was measured by the FIR technique.