Optical fiber sensor employing soaking discoloration ink for water immersion detection

The superior performance of an optical fiber sensor employing soaking discoloration ink for water sensing is demonstrated. The proposed sensor, possessing low-cost, easily do-it-yourself and highly sensitive features, is very suitable for deploying in existing optical fiber networks to detect water immersion. The discrimination is over 3.5 dB, which can be easily measured by an OTDR.