Conventional
thermometers fail to operate in a variety of medical
procedures due to the harsh and sensitive environments required for
such applications, and therefore, the development of optical fiber
thermometers has gained significant attention. In this study, a ZnO–SrAl2O4:Eu (ZnO–SAO:Eu) nanocomposite has been
synthesized by using a CO2 laser, which showed enhanced
optical properties and a dynamic range in comparison with the crystalline
ones. XRD, EDAX, SEM, and PL spectroscopy investigated the crystalline
and optical properties of precursors, and the final nanostructure,
and the findings were in agreement with references. Further analysis
of the PL spectra in a 0–100 °C range suggests that the
optical properties of the ZnO–SAO:Eu nanocomposite show a linear
behavior toward temperature alterations. Considering this inter-relation
and measuring the decay time for various frequencies helped us calibrate
the temperature based on phase angle shift alterations. The curve
obtained at 30 Hz frequency exhibits the highest linearity and accuracy
(0.33%) due to its relatively high phase shift (60 °C) in the
studied temperature range. The fabricated sensor exhibited great sensitivity
and repeatability while maintaining an unprecedented structure. Finally,
the thermometer’s applicability for future industries was tested
by measuring the interior temperature of a dead muscle tissue as it
was being heated by a diode laser and it was accompanied by remarkable
results. This achievement could make this device a promising addition
to the drug delivery science and industry as it could aid the study
and optimization of medications that increase the targeted tissues
temperature and therefore can be employed in treating tumors that
are formed in organic tissues.