In this paper, we propose and experimentally investigate a linearly polarized narrow-linewidth random fiber laser(RFL) operating at 1080 nm and boost the output power to kilowatt level with near-diffraction-limited be...In this paper, we propose and experimentally investigate a linearly polarized narrow-linewidth random fiber laser(RFL) operating at 1080 nm and boost the output power to kilowatt level with near-diffraction-limited beam quality using a master oscillation power amplifier. The RFL based on a half-opened cavity, which is composed of a linearly polarized narrow-linewidth fiber Bragg grating and a 500 m piece of polarization-maintained Ge-doped fiber, generates a 0.71 W seed laser with an 88 pm full width at half-maximum(FWHM) linewidth and a 22.5 dB polarization extinction ratio(PER) for power scaling. A two-stage fiber amplifier enhances the seed laser to the maximal 1.01 k W with a PER value of 17 dB and a beam quality of M_x^2=1.15 and M_y^2=1.13. No stimulated Brillouin scattering effect is observed at the ultimate power level, and the FWHM linewidth of the amplified random laser broadens linearly as a function of the output power with a coefficient of about 0.1237 pm∕W.To the best of our knowledge, this is the first demonstration of a linearly polarized narrow-linewidth RFL with even kilowatt-level near-diffraction-limited output, and further performance scaling is ongoing.展开更多
We propose a B-integral management strategy for manipulating the nonlinear effects by employing a discrete singlecrystal fiber(SCF)configuration,enabling direct amplification of 2-μm femtosecond pulses at high repeti...We propose a B-integral management strategy for manipulating the nonlinear effects by employing a discrete singlecrystal fiber(SCF)configuration,enabling direct amplification of 2-μm femtosecond pulses at high repetition rates without additional pulse picking,stretching and compression.The system delivers an average power of more than 56 W at 75.45 MHz with extremely high extraction efficiency(>55%)and near-diffraction-limited beam quality(M^(2)<1.2).The dynamic evolution of the optical spectra and temporal properties in the power amplifier reveals that detrimental nonlinear effects are largely suppressed due to the low accumulated nonlinear phase shift in the discrete SCF layout.This straightforward,compact and relatively simple approach is expected to open a new route to the amplification of 2-μm ultrashort pulses at MHz and kHz repetition rates to achieve high average/peak powers,thereby offering exciting prospects for applications in modern nonlinear photonics.展开更多
基金National Natural Science Foundation of China(NSFC)(61322505,61635005)
文摘In this paper, we propose and experimentally investigate a linearly polarized narrow-linewidth random fiber laser(RFL) operating at 1080 nm and boost the output power to kilowatt level with near-diffraction-limited beam quality using a master oscillation power amplifier. The RFL based on a half-opened cavity, which is composed of a linearly polarized narrow-linewidth fiber Bragg grating and a 500 m piece of polarization-maintained Ge-doped fiber, generates a 0.71 W seed laser with an 88 pm full width at half-maximum(FWHM) linewidth and a 22.5 dB polarization extinction ratio(PER) for power scaling. A two-stage fiber amplifier enhances the seed laser to the maximal 1.01 k W with a PER value of 17 dB and a beam quality of M_x^2=1.15 and M_y^2=1.13. No stimulated Brillouin scattering effect is observed at the ultimate power level, and the FWHM linewidth of the amplified random laser broadens linearly as a function of the output power with a coefficient of about 0.1237 pm∕W.To the best of our knowledge, this is the first demonstration of a linearly polarized narrow-linewidth RFL with even kilowatt-level near-diffraction-limited output, and further performance scaling is ongoing.
基金financially supported by the National Natural Science Foundation of China (Grant Nos.62475106,U23A20558,52025021 and 52032009)the Natural Science Foundation of Shandong Province,China (Grant No.ZR2024ZD16)+1 种基金the Foundation of the National Key Laboratory of Plasma Physics (Grant No.6142A04230301)financial support from the Qilu Young Scholars Program of Shandong University
文摘We propose a B-integral management strategy for manipulating the nonlinear effects by employing a discrete singlecrystal fiber(SCF)configuration,enabling direct amplification of 2-μm femtosecond pulses at high repetition rates without additional pulse picking,stretching and compression.The system delivers an average power of more than 56 W at 75.45 MHz with extremely high extraction efficiency(>55%)and near-diffraction-limited beam quality(M^(2)<1.2).The dynamic evolution of the optical spectra and temporal properties in the power amplifier reveals that detrimental nonlinear effects are largely suppressed due to the low accumulated nonlinear phase shift in the discrete SCF layout.This straightforward,compact and relatively simple approach is expected to open a new route to the amplification of 2-μm ultrashort pulses at MHz and kHz repetition rates to achieve high average/peak powers,thereby offering exciting prospects for applications in modern nonlinear photonics.
