High-power single-frequency fiber lasers with diffraction-limited spots are indispensable for a wide range of photonic applications and are particularly in advanced detection and sensing technologies.However,the simul...High-power single-frequency fiber lasers with diffraction-limited spots are indispensable for a wide range of photonic applications and are particularly in advanced detection and sensing technologies.However,the simultaneous achievement of kilowatt-level output power and diffraction-limited beam quality has remained elusive in all reported single-frequency fiber laser systems to date,primarily due to limitations imposed by the stimulated Brillouin scattering(SBS)effect and transverse mode instability(TMI)effect.In this study,we demonstrate the design and manufacturing of an ultra-low numerical aperture(NA)functional Yb-doped fiber featuring a bat-type refractive index distribution,specifically engineered for single-frequency laser amplification.In the fabrication,we implemented multiple chelate gas filling and particle deposition iterations,leading to an active fiber with a bat-type refractive index distribution.The unique capabilities of this large mode area and high-order modes leakage fiber(HOMLF)were demonstrated by stably amplifying the single-frequency laser with more than one kilowatt output power and near single mode beam quality(M_(x)^(2)=1.10,M_(x)^(2)=1.18)for the first time.This fiber design advances the leap forward in single-frequency fiber lasers,which could contribute as a novel and efficient laser amplification technique for the next generation of gravitational wave detection systems.展开更多
基金support from the National Key Research and Development Program of China(2022YFB3606400).
文摘High-power single-frequency fiber lasers with diffraction-limited spots are indispensable for a wide range of photonic applications and are particularly in advanced detection and sensing technologies.However,the simultaneous achievement of kilowatt-level output power and diffraction-limited beam quality has remained elusive in all reported single-frequency fiber laser systems to date,primarily due to limitations imposed by the stimulated Brillouin scattering(SBS)effect and transverse mode instability(TMI)effect.In this study,we demonstrate the design and manufacturing of an ultra-low numerical aperture(NA)functional Yb-doped fiber featuring a bat-type refractive index distribution,specifically engineered for single-frequency laser amplification.In the fabrication,we implemented multiple chelate gas filling and particle deposition iterations,leading to an active fiber with a bat-type refractive index distribution.The unique capabilities of this large mode area and high-order modes leakage fiber(HOMLF)were demonstrated by stably amplifying the single-frequency laser with more than one kilowatt output power and near single mode beam quality(M_(x)^(2)=1.10,M_(x)^(2)=1.18)for the first time.This fiber design advances the leap forward in single-frequency fiber lasers,which could contribute as a novel and efficient laser amplification technique for the next generation of gravitational wave detection systems.
