A dissolved oxygen sensor based on ruthenium fluorescence and u-shaped plastic optical fiber

A dissolved oxygen sensor based on ruthenium(Ru) fluorescence and U-shape plastic optical fiber (POF) was described. Dichlorotris (1, 10-phenanthroline) ruthenium (II) was used as an oxygen indicator, which was coated on to the surface of a 1mm diameter U-shaped POF. Phase modulation technique is used to measure fluorescence lifetime. The phase difference between 100% and 0% dissolved oxygen is 1.78 degree. By using the nonlinear assumption, we also calculate that the there are only 20% thickness of the sensor material is affected by DO.