KEYWORDS: Luminescence, Erbium, Temperature metrology, Glasses, Temperature sensors, Barium, Borosilicate glass, Semiconductor lasers, Ions, Energy transfer
The process of preparing Er3 +-doped barium borosilicate glass samples with different dopant concentrations using a high-temperature sintering technique is discussed. Under a 978-nm semiconductor laser excitation, the energy transfer from 2H11/2 to 4I15/2 and 4S3/2 to 4I15/2 caused by the transitions of Er3 + ions yields a 534- and a 549-nm green fluorescence. The relationship between the absolute temperature T and the fluorescence intensity ratio R of these two up-conversion photoluminescence spectra is discussed and fitted to the exponential function R = 1.782exp ( − 328/T) in the temperature range of 298 to 698 K. The sensitivity of the samples descends monotonously from 0.00219 to 0.00075 K−1 with the temperature increase from 298 to 698 K. The data are of undoubted repeatability, and the proposed doped glass is suitable for sensitive, high-temperature measurement.
In order to improve control precision of the piezoelectric ceramics (PZT) micro-displacement system, a self-adaptive
fuzzy Proportional Integration Differential (PID) controller is designed based on the traditional digital PID controller
combining with fuzzy control. The arithmetic gives a fuzzy control rule table with the fuzzy control rule and fuzzy
reasoning, through this table, the PID parameters can be adjusted online in real time control. Furthermore, the automatic
selective control is achieved according to the change of the error. The controller combines the good dynamic capability
of the fuzzy control and the high stable precision of the PID control, adopts the method of using fuzzy control and PID
control in different segments of time. In the initial and middle stage of the transition process of system, that is, when the
error is larger than the value, fuzzy control is used to adjust control variable. It makes full use of the fast response of the
fuzzy control. And when the error is smaller than the value, the system is about to be in the steady state, PID control is
adopted to eliminate static error. The problems of PZT existing in the field of precise positioning are overcome. The
results of the experiments prove that the project is correct and practicable.
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