Temperature Dependence of Cutoff Wavelength in Bi/Er Co-Doped Fiber

Temperature dependence of cutoff wavelength of Bi/Er co-doped fiber (BEDF) is investigated. In temperature range from 23°C to 500°C, effective cutoff wavelength of BEDF is found to be a linear function of temperature, shifting from 912 nm to 946 nm at a rate of ~ 76 pm/°C. The difference of thermal expansion coefficient (TEC) between core and cladding is believed to be the dominant factor leading to the observed phenomenon.