The Study Of Luminescence Properties And Application Of Novel Bismuth- Doped Optical Fiber

With the rapid development of Internet of Things and cloud computing, the amount of information in the world increase exponentially. So the demand on the communication capacity and bandwidth of the optical fiber are increasingly high. At present,the commercial erbium-doped fiber amplifier and laser work in C+L band normally, which will limit the communication capacity of the optical fiber. However,with the technology improvement of optical fiber production, the low loss communication band of silica fiber has been extended to O, E, S, C, L and U bands.Therefore, it is urgent to develop ultra-broadband fiber amplifiers and fiber lasers that covering the whole communication window for future high rate communication. The near infrared radiation spectrum of bismuth doped fiber can cover 1000-1500 um and 1600-1775 nm while the novel bismuth and erbium co-doped fiber (BEDF) can even cover the entire 1000-1700 nm band. They can be used to fabricate ultra-broadband fiber amplifiers and fiber lasers that used in telecommunication systems. In addition,they can also be used to fabricate ultra broadband light source for the intelligent optical fiber sensor networks. In this paper, the near infrared fluorescence and amplification characteristics of BEDF as well as its application in wavelength division multiplexed fiber Bragg grating sensing system are studied. The main work includes:(1) Near infrared fluorescence and gain properties of the novel BEDF are investigated. The influence of the pump power, pump wavelength, fiber length and temperature on the fluorescence characteristics are analyzed systematically. The small signal gain of three bands, 1460 nm, 1535 nm and 1550 nm, are investigated under a 830 nm laser diode pumping. The bismuth doped concentration is one order of magnitude lower than that of erbium doped concentration in our work, which is different from the previous fiber we studied, in which the bismuth and erbium concentration are in the same level.(2) An ultra-broadband light source is fabricated by using BEDF, and the output spectrum and stability of light source are studied systematically. When it is pumped by 830 nm laser diode, the output light of the light source can cover 980-1630 nm and the full width at half maximum (FWHM) is up to 525 nm. The standard deviation of output spectrum is less than 0.05 dB, showing very good stability.(3) BEDF ultra-broadband light source was used in wavelength division multiplexing fiber Bragg grating (FBG) sensing system, and strain sensing at O band and C band have been achieved. Experimental results demonstrate that, the multiplexing capacity of the sensing system will be greatly improved by using BEDF based ultra-broadband light sources. Especially, the super-large scale sensor networks can be constructed to monitor large structures, and the crosstalk between the fiber gratings is very small.