Phys.org December 15, 2023
An international team of researchers (Belgium, Greece, Czech Republic) showed described in detail the process to obtain a fully packaged miniature photonic temperature sensor starting from bare PIC dies having Bragg grating sensors in a silicon waveguide. The PIC was interfaced from the back side using a 300 ÎĽm ball lens ensuring that the top surface remained clear of any interfacing fibers. Based on this they developed a solution for integrating a 1 mm Ă— 1 mm sensor PIC with a single-mode fiber and packaging it in a 1.5 mm inner-diameter metal protective tube. A packaged sensor was achieved by sequentially mounting the holder on a ceramic ferrule and then the PIC on the holder and finally gluing a protective metal tube surrounding the assembly, taking care that the PIC surface was flush with the end face of the tube. They demonstrated a packaged phase-shifted silicon Bragg grating temperature sensor operating around 1550 nm, which could be read out in reflection using a commercial interrogator. They demonstrated sensor functionality up to 180°C… read more. Open Access TECHNICAL ARTICLEÂ
Typical measured reflection spectra of the phase-shifted Bragg gratings in TE silicon waveguides at three different pitches… Credit: Journal of Optical Microsystems, 2 December 2023Â