Fusion Splice Of Photonic Crystal Fibers And Application In High Power Supercontinuum

Supercontinuum(SC) has been applied in optical fields such as biomedicine,laser measurement and optical communication more and more. Recently, to generate supercontinuum in photonic crystal fiber (PCF) by femtosecond laser pulses has become the frontier of research. To improve output power of supercontinuum has very important significance in expanding its application. Because of PCF's special structure it can be broken more easily than conventional fibers, thus limiting output power of supercontinuum. We analyzed the mechanism of fusion splicing loss and how the splicing parameters affects the splicing loss. On this basis, we proposed three solutions to improve output power of supercontinuum. We conducted theoretical studies and experimental verifications and got the desired results.We firstly studied the fusion splicings of different types of PCFs with single-mode fibers(SMFs). For different types of PCFs we obtained low-loss fusion splicings. The PCFs were used in supercontinuum experiments to take advantage of SMFs'high damage threshold and high coupling efficiency to improve the output power. As a result, a 7.45W high power supercontinuum was obtained.But the power of dissipation of light produced by splicing loss limits the further improvement of output power, so we carried out experiments of fiber polishing, The polished PCFs were used in supercontinuum experiments, as a result, coupling efficiency improved from 60% to 80% and a 6.40W high power supercontinuum was obtained.In order to extend the spectrum to the short-wave direction while improving output power of supercontinuum, we conducted experiments of fusion splicings of PCFs with tapered fibers. We obtained a low-loss fusion splicing of PCFs with tapered fibers and splice loss decreased from 4.61dB to 1.49dB. A wide coverage high power supercontinuum is expected to be obtained via this program.