Specialty Optical Fibers Handbook

air holes of the fiber absorb the guided light through a long interaction length.

A drawback of the PBG fiber sensors, comparing to the D-shape fiber sensors, is

that the response time for the former should be much longer because of the small

diameter of the air holes for the gas to be filled in. Third, the sensitivity also

depends on the resolution or the spectral detection scheme. A narrow line width

and wavelength-tunable light source of a high spectral resolution spectrometer is

crucial. When the source line width exceeds the absorption line width, the

maximum detected signal expressed as a fraction of the detected optical power

decays linearly with the increase in source line width signal. Diode lasers with

distributed feedback (DFB) architectures ...