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[en] There is a long history of using the Er3+ ion’s 2H11/2/4S3/2–4I15/2 transitions for ratiometric thermal sensing. As demonstrated previously, these two transitions can be triggered via up- and down-conversion mechanisms. However, little attention is focused on the influence of these two mechanisms on the sensing performance for the 2H11/2/4S3/2–4I15/2 transitions. It was demonstrated here the as-prepared CaWO4:Yb3+, Er3+ phosphors could be effectively triggered by both the 980 and 405 nm laser diodes to generate the 2H11/2/4S3/2–4I15/2 transitions via up- and down-conversion mechanisms, respectively. Therefore, up- and down-conversion dual-mode optical thermometry was achieved in one micro-sized thermometer, which allowed us to study the difference between the two methods. Two of the most important evaluating parameters for temperature sensors, e.g., the relative sensitivity and the temperature resolution, were studied and compared upon excitations at 980 and 405 nm. It was confirmed that no obvious difference was observed in these two cases. What’s more, it was demonstrated the 980 nm laser diode, compared with the 405 nm one, aroused more heat for the as-prepared samples. It may help us to select proper excitation sources in different situations. (paper)
[en] We experimentally demonstrate the control of the single and two-photon fluorescence (SPF and TPF) in Er3+ ions by shaping the femtosecond laser pulse with a π or square phase modulation. With the low laser intensity (8.4 × 1010 W/cm2), SPF keeps a constant while TPF is effectively suppressed by the two control schemes. With the high laser intensity (1.2 × 1013 W/cm2), both SPF and TPF are simultaneously enhanced or suppressed by the π phase modulation, and SPF is enhanced while TPF is effectively suppressed by the square phase modulation. The up/down-conversion fluorescence enhancement, suppression, or tuning by the optical control method can greatly expand its applications in various related fields
[en] The laser source with 3 μm/2 μm output wavelength has many application prospects in clinical medicine, photoelectric countermeasure, and scientific research measurement. An Er3+ doped ZBLAN fiber laser with output wavelength of 2 .8 μm and 1 .6 μm is experimentally studied. By setting the pump power to 5 W, a continuous dual-wavelength output with a central wavelength of 2.803 μm and 1.61 μm is obtained and the corresponding maximum output power is 362.4 mW and 108.6 mW. The slope efficiency is 12.1% and 4.94% respectively. What’s more, the slope efficiency is 12.1% and 4.94% respectively, and the fluctuation rates of peak power of the two wavelengths are 9.7% and 2.1% within 4 h which indicate that the laser has relatively good stability.
[en] Er3+ and/or Yb3+ doped Sr2ScF7 up-conversion (UC) phosphors were synthesized, and the optimum doping concentrations of Yb3+ and Er3+ in the Sr2ScF7 host were found to be 20% mol and 7% mol, respectively. Under excitation of 980 nm laser, the UC spectra of the samples is composed of three green emission bands from 510 to 570 nm centered at 525, 543 and 551 nm and two red emission band from 640 to 690 nm with two peaks at 657 and 671 nm, which is attributed to the 2H11/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3+, respectively. The UC emission color of Er3+ can be tuned by adjusting the intensity ratio of red to green emission through manipulating the population of red and green emitting states.
[en] We report on the interplay between experimental arrangement, resonant radiation trapping and decay measurements of infra-red emission of erbium doped glasses. The impact of the relative position between the exciting and detecting positions of the bulk samples is investigated. We show that the radiation trapping leads to long rise time dynamics evenly distributed outside the pulsed pumped region.
[en] The fluorescence properties in IR region of fluorotellurite glass with high Er3+ concentration up to 13 mol% are investigated and optimum concentration of 2.7 µm emission is 11 mol%, followed by a decrease in fluorescence intensity. The thermal characteristic parameter (ΔT = 98 °C) based on DSC curve shows a good thermal stability. The FWHM corresponding to 1.5 µm broadens as Er3+ increases and reaches a maximum of 110 nm (13 mol%) which shows superior bandwidth properties. The high amplifier gain value(σemi × τmea) of 11.87 × 10-21 cm2 ms, along with longer lifetime (1.72 ms), which benefits from the low phonon energy (612 cm−1) and hydroxyl content (0.03 cm−1), indicates the ideal 2.7 µm laser characteristics. Hopefully, the glass studied here may be find potential applications in the fields of fiber amplifier and MIR microchip lasers.