Reflectivity of Bragg grating fiber on human respiration using InGaAs photodiode converter system Dian Putri Oktavia ; Saktioto Saktioto ; Dwi Hanto ; Syamsudhuha Syamsudhuha ; Rina Amelia ; Tengku Emrinaldi Komunikasi Fisika Indonesia 8 Sep 2026 10.31258/jkfi.22.2.175-178
