A superfluorescent fiber source (SFS) with the low Ge-doped and Er/Ce codoped photonic crystal fiber (ECPCF) is proposed to improve the radiation resistance of SFS. The radiation effects of SFSs for an Er/Ce codoped conventional fiber (ECF) and a low Ge-doped and ECPCF are investigated in a Co60 gamma-ray environment. Results show that the low Ge-doped photonic crystal fiber exhibits better radiation tolerance than its counterpart in the Er/Ce codoped fibers, and the attenuation of the power of ECPCF-SFS is significantly smaller than that of ECF-SFS. In addition, the radiation-induced spectral variation of ECPCF-SFS with increased radiation dose is less than that of ECF-SFS. ECPCF-SFS simultaneously exhibits higher recovery performance than ECF-SFS.
An ultra-flat and ultra-broadband supercontinuum (SC) is demonstrated in a 4-m photonic crystal fiber (PCF) pumped by an Yb-doped all-fiber noise-like pulses (NLP) laser. The Yb-doped fiber laser is seeded by a SESAM mode-locked fiber laser, and amplified by cascaded fiber amplifiers, with its center wavelength, repetition frequency and the average noise-like bunch duration of 1064.52 nm, 50.18 MHz, 9.14 ps, respectively. Pumped by this NLP laser, the SC source has a 3 dB bandwidth and a 7 dB bandwidth (ignore the pump residue) of 1440 nm and 1790 nm at the maximum average output power of 6.94 W. To the best of our knowledge, this flatness is significantly prominent for the performance of PCF-based SC sources.
The radiation resistance effect of two superfluorescent fiber sources using Er-doped photonic crystal fiber is studied under 500 Gy gamma-ray irradiation. One is trimmed into a quasi-Gaussian spectrum by a filter and the other is not trimmed. The results show that the SFS with spectrum trimming has a smaller radiation induced attenuation and a higher mean wavelength stability (2.616 dB and 24.803 ppm) than that of the SFS without spectrum trimming (3.187 dB and 611.766 ppm). Therefore, this method has practical use for improving radiation resistance in space environment.
A high-stability erbium-doped superfluorescent photonic crystal fiber source (SPCFS) is presented. Optimization of
the high-stable SPCFS is achieved by combining high-performance EDPCF, optimal fiber length, and source
structure with suitable pump power. The result shows a 56.979 ppm mean wavelength stability of a prototype SPCFS
is demonstrated with the temperature varied in the range of −40 °C—70 °C. Especially, in the room temperature, the
mean wavelength stability of a prototype SPCFS is less than 2.59 ppm, which will be approaching the requirement
for inertial-grade fiber optic gyroscopes.
A high-stable and broadband single-pass backward configuration superfluorescent fiber source based on erbium-doped photonic crystal fiber (EDPCF) is proposed. With the proper EDPCF length, pump power, and a gain flattening filter, we demonstrate that it is possible to create a high-stable and broadband erbium-doped superfluorescent photonic crystal fiber source (SPCFS). This was accomplished by replacing the conventional erbium-doped fiber with the EDPCF, the intrinsic thermal coefficient of which is four times less than the measured conventional erbium-doped fibers. The SPCFS showed that the total output power stability was less than 0.0337%, the 3-dB spectral width was broader than 42 nm, the output spectrum flatness was less than 1 dB, and the mean wavelength stability was less than 2.58 ppm over 6 h at temperatures from 24.3°C to 25.5°C, which approached the requirement for inertial-grade fiber optic gyroscopes.