Ultraviolet-extended Supercontinuum Generation in Zero-dispersion Wavelength Decreasing Photonic Crystal Fibers

Wanjun Bi, Xia Li, Meisong Liao, Tianxing Wang, Peiwen Kuan, Liang Chen, Lili Hu, Weiqing Gao
2020 IEEE Photonics Journal  
Supercontinuum covering the ultraviolet-blue region is highly useful for fluorescence microscopy. Four zero-dispersion wavelength decreasing photonic crystal fibers with different fiber cross structures and taper profiles are fabricated to extend the short wavelength edge of supercontinuum. Both nanosecond and picosecond pump pulses at 1 μm are used to generate supercontinuum. With a 3 ns pump pulse, the short wavelength edge of supercontinuum is extended to below 400 nm in a fiber with high
more » ... fiber with high air-hole ratio (named T3). The underlying mechanism of supercontinuum generation is explored. The short and long wavelength edges of supercontinuum are highly related with the phase-matching condition which decided by the group velocity curve of fiber small core end. With a 10 ps pump pulse, the spectral intensity around ~800 nm increases in all four fibers. However, the intensity in shorter wavelength band decreased in fibers with a high air-hole ratio (named T3, T4). The experimental results imply that a zero-dispersion wavelength decreasing photonic crystal fiber suitable for nanosecond pulse pumping is not necessarily suitable for picosecond pulse pumping, especially for fibers with high air-hole ratio. This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/ This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/JPHOT.2020.3034235, IEEE Photonics Journal This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/ This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/JPHOT.2020.3034235, IEEE Photonics Journal ZDW decreasing PCF suitable for nanosecond pulse pumping is not necessarily suitable for picosecond pulse pumping, especially for fibers with large air-hole ratio. This investigation provides practical guidance to designing PCF with decreasing ZDW: (1) ZDW decreasing PCF with high air-hole ratio is more suitable for nanosecond pump pulse. (2) The ZDW when soliton fission occurs is of vital importance, determining the position of initial DW and SC flatness.
doi:10.1109/jphot.2020.3034235 fatcat:dwwblofrdbdm5baupenp5qdhiu