Gas detection with micro- and nano-engineered optical fibers

This paper overviews recent development in gas detection with micro- and nano-engineered optical fibers, including hollow-core fibers, suspended-core fibers, tapered optical micro/nano fibers, and fiber-tip micro-cavities. Both direct absorption and photoacoustic spectroscopy based detection schemes are discussed. Emphasis is placed on post-processing stock optical fibers to achieve better system performance. Our recent demonstration of distributed methane detection with a ∼75-m long of hollow-core photonic bandgap fiber is also reported.