**5.1 Modified SMF fabrication and characterizations**

Three types of modified SMF platforms including etched, tapered and etchedtapered platforms were developed and investigated towards ammonia at room temperature. A standard SMF-28 single mode silica fiber (Lucent All-Wave Fiber, 9/125 μm core/cladding diameter ratio) is modified as the optical transducing platforms for NH3 sensing applications. Each transducing platform was made of 1 m length of SMF. The Tafzel ® polymer jacket enfolding the SMF was removed mechanically over 8 cm by a fiber a stripper. The fabrication processes for the three types of modified SMF platform will be elaborated in the following subsections [2, 11].
