Reflection-mode fiber-optic temperature sensing probe based on quantum dots filled micro-cavity

We report a prototype reflection-mode fiber optic probe based on quantum dots filled micro-cavity. The probe was fabricated by sealing quantum dots liquid or coating inside a glass capillary pigtailed with a multimode optical fiber. And the probe was tested for in situ measurement of temperature change. By analyzing the back-reflected fluorescence signals generated from the quantum dots, the localized temperature of the micro-cavity structure could be correlated. The sensitivities based on fluorescence peak wavelength and full-width at half-maximum (FWHM) were calculated for both sensors in the biologically meaningful temperature range of 33.0-42.0C. This proposed reflection-mode trumpet-shape micro-cavity probe is attractive for chemical and biological sensing because it is cost-effective, simple to fabricate, mechanically robust and miniaturized in size.