Performance improvement of optical fibre oxygen sensor detection scheme incorporating narrow bandpass emission optical filter

We report performance improvement of an optical fibre oxygen sensor based on direct measurement fluorescence quenching of oxygen sensitive ruthenium complex and indirect measurement of lifetime through phase fluorometry. Comparison between detection scheme with and without emission filters using various bandpass ranges are being investigated. A 1.7 fold increase in fluorescence intensity is observed with a detection scheme employing broad (195 nm) bandpass emission filter compared to a system without emission filter. Six fold increase in fluorescence emission is detected when a narrow (25 nm) emission filter is adopted in the system. Similarly, six fold increase in phase angle value φ_ω is demonstrated in an in-direct O₂ sensor measurement when 25 nm bandpass emission filter is employed in such system. Improvement in O₂ sensor sensitivity and linearity are also reported with the inclusion of narrow bandpass emission filter.