Erbium-doped silica fibers for intrinsic fiber-optic temperature sensors

Abstract

The variation in the green intensity ratio ((2)H(11/2) and (4)S(3/2) energy levels to the ground state) of Er ions in silica fibers has been studied as a function of temperature. The different processes that are used to determine the population of these levels are investigated, in particular 800-nm excited-state absorption in Er-doped fibers and 980-nm energy transfer, in Yb-Er-codoped fibers. The invariance of the intensity ratio at a fixed temperature with respect to power, wavelength, and doped fiber length has been investigated and shown to permit the realization of a high-dynamic-range (greater than 600 °C), autocalibrated fiber-optic temperature sensor.

Thermal effect on up-conversion in Er3+/Yb3+ co-doped silicate glass

“…It was obtained that the maximum sensitivity value of 0.0031/K is reached at 550 K. Using the upconversion spectrum intensity ratio of Yb 3+ -Er 3+ silicate glasses, we can easily make fiber and waveguide sensor to measure temperature by employing a scanning spectrograph. The application of the FIR method in temperature measurement was investigated with the chalcogenide glass and ZBLAN, which showed promising development due to independence of variations in the excitation power [16,17]. But due to the high vitreous transition temperature, the silicate glass can be applied to measure temperature until 850 K.…”

1550-nm fluorescence efficiency and heat generation of erbium-doped fiber pumped by pulsed and quasi-continuous-wave lasers

“…Two prominent peaks occur at the wavelengths of 538 nm and 547 nm. Those two peaks correspond to the transitions from the thermalized states ( 2 H 11/2 and 4 S 3/2 ) to the ground state [3]. The intensity ratio R is defined as R = I H /I S = C exp(− E/kT ) [3].…”

“…Those two peaks correspond to the transitions from the thermalized states ( 2 H 11/2 and 4 S 3/2 ) to the ground state [3]. The intensity ratio R is defined as R = I H /I S = C exp(− E/kT ) [3]. In this equation, I H (I S ) corresponds to the emitted intensity from 2 H 11/2 ( 4 S 3/2 ) state to ground state.…”

“…EDFs can be pumped by green, red, or near-infrared electromagnetic waves, generating 1550-nm fluorescence [14] and up-converted green light [3]. The power requirement for EDF amplifiers pumped in the 800, 980, and 1480 nm bands has been discussed by B. Pedersen [4].…”

A fiber optic temperature sensor based on the combination of epoxy and glass particles with different thermo-optic coefficients

“…Commercially, available fiber optic temperature sensors often use a semiconductor-chip, which has an absorption edge that moves with the temperature [5,6]. Other sensors utilize Bragg gratings [7][8][9] or the temperature-dependent fluorescence intensity of certain materials [10] to measure the temperature. Another way is to analyze the Raman scattering in a glass fiber [11] or to analyze the temperature with a Fabry-Pérot interferometer (FPI) [12,13] or with a Mach-Zehnder interferometer [14] integrated into an optic fiber.…”