In this paper, we report our recent research progresses on the design, fabrication and characterization of photonic sensors for harsh environment applications, with the help of novel Integrated Additive and Subtractive Manufacturing (IASM) system. Glass 3D printing with direct laser melting process in this IASM system presents the dimension accuracy on the order of tens or hundreds of microns. The addition of laser micromachining allows the fabrication of structures with micron dimension accuracy, showing the unique advantage of IASM system in high dimensional accuracy compared with traditional 3D printing process. A number of photonic sensors and devices will be summarized and presented, including (1) 3D printed all-glass fiber-optic pressure sensor for high temperature applications, (2) Information integrated glass module fabricated by IASM and (3) IASM for microfluidic pressure sensor fabrication.
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 microcavity 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.