Absorption detection of cobalt(II) ions in an index-guiding microstructured optical fiber

Abstract We reported the absorption detection of cobalt(II) ions (Co 2+ ) in aqueous solutions which is filled into the air-holes of a pure-silica microstructured optical fiber (MOF). The evanescent field in MOF which changes with solution of absorbing species is numerically investigated with respect to the change of refractive index, wavelength as well as the microstructure pattern in a systematic manner. Good linear calibration curves for samples concentration and length of MOF were obtained. Moreover, the MOF possesses good thermal and bending stabilities, thus allowing its use for absorption detection of an analytes even in harsh environment. The MOF may be developed into absorption sensors or integrated with microchips.