Rare earth-doped fibres are a diode-pumped,solid-state laser architecture that is highly scalable in average power.The performance of pulsed fibre laser systems is restricted due to nonlinear effects.Hence,fibre desig...Rare earth-doped fibres are a diode-pumped,solid-state laser architecture that is highly scalable in average power.The performance of pulsed fibre laser systems is restricted due to nonlinear effects.Hence,fibre designs that allow for very large mode areas at high average powers with diffraction-limited beam quality are of enormous interest.Ytterbium-doped,rod-type,large-pitch fibres(LPF)enable extreme fibre dimensions,i.e.,effective single-mode fibres with mode sizes exceeding 100 times the wavelength of the guided radiation,by exploiting the novel concept of delocalisation of higher-order transverse modes.The non-resonant nature of the operating principle makes LPF suitable for high power extraction.This design allows for an unparalleled level of performance in pulsed fibre lasers.展开更多
We report on the high-power amplification of a 1064 nm linearly polarized laser in an all-fiber polarizationmaintained master oscillator power amplifier,which can operate at an output power level of 1.3 kW.The beam qu...We report on the high-power amplification of a 1064 nm linearly polarized laser in an all-fiber polarizationmaintained master oscillator power amplifier,which can operate at an output power level of 1.3 kW.The beam quality(M^2) was measured to be <1.2 at full power operation.The polarization extinction rate of the fiber amplifier was measured to be above 94% before mode instabilities(MIs) set in,which reduced to about 90% after the onset of MI.The power scaling capability of strategies for suppressing MI is analyzed based on a semianalytical model,the theoretical results of which agree with the experimental results.It shows that mitigating MI by coiling the gain fiber is an effective and practical method in standard double-cladding large mode area fiber,and,by tight coiling of the gain fiber to the radius of 5.5 cm,the MI threshold can be increased to three times higher than that without coiling or loose coiling.Experimental studies have been carried out to verify the idea,which has proved that MI was suppressed successfully in the amplifier by proper coiling.展开更多
基金The research leading to these results received funding from the European Research Council under the European Union’s Seventh Framework Programme(FP7/2007-2013)/ERC Grant Agreement No.[240460]the Thuringian Ministry of Education,Science and Culture under contract PE203-2-1(MOFA)and contract B514-10061(Green Photonics).FJ acknowledges financial support from the Abbe School of Photonics.
文摘Rare earth-doped fibres are a diode-pumped,solid-state laser architecture that is highly scalable in average power.The performance of pulsed fibre laser systems is restricted due to nonlinear effects.Hence,fibre designs that allow for very large mode areas at high average powers with diffraction-limited beam quality are of enormous interest.Ytterbium-doped,rod-type,large-pitch fibres(LPF)enable extreme fibre dimensions,i.e.,effective single-mode fibres with mode sizes exceeding 100 times the wavelength of the guided radiation,by exploiting the novel concept of delocalisation of higher-order transverse modes.The non-resonant nature of the operating principle makes LPF suitable for high power extraction.This design allows for an unparalleled level of performance in pulsed fibre lasers.
基金funding from the program for the National Science Foundation of China under Grant No.61322505the program for New Century Excellent Talents in University+1 种基金the Innovation Foundation for Excellent Graduates in National University of Defense Technology under Grant No.B120704the Hunan Provincial Innovation Foundation for Postgraduate under Grant No.CX2012B035
文摘We report on the high-power amplification of a 1064 nm linearly polarized laser in an all-fiber polarizationmaintained master oscillator power amplifier,which can operate at an output power level of 1.3 kW.The beam quality(M^2) was measured to be <1.2 at full power operation.The polarization extinction rate of the fiber amplifier was measured to be above 94% before mode instabilities(MIs) set in,which reduced to about 90% after the onset of MI.The power scaling capability of strategies for suppressing MI is analyzed based on a semianalytical model,the theoretical results of which agree with the experimental results.It shows that mitigating MI by coiling the gain fiber is an effective and practical method in standard double-cladding large mode area fiber,and,by tight coiling of the gain fiber to the radius of 5.5 cm,the MI threshold can be increased to three times higher than that without coiling or loose coiling.Experimental studies have been carried out to verify the idea,which has proved that MI was suppressed successfully in the amplifier by proper coiling.
