The phase summation effect in sum-frequency mixing process is utilized to avoid a nonlinearity obstacle in the power scaling of single-frequency visible or ultraviolet lasers.Two single-frequency fundamental lasers ar...The phase summation effect in sum-frequency mixing process is utilized to avoid a nonlinearity obstacle in the power scaling of single-frequency visible or ultraviolet lasers.Two single-frequency fundamental lasers are spectrally broadened by phase modulation to suppress stimulated Brillouin scattering in fiber amplifier and achieve higher power.After sum-frequency mixing in a nonlinear optical crystal,the upconverted laser returns to single frequency due to phase summation,when the phase modulations on two fundamental lasers have a similar amplitude but opposite sign.The method was experimentally proved in a Raman fiber amplifier-based laser system,which generated a power-scalable sideband-free single-frequency 590 nm laser.The proposal manifests the importance of phase operation in wave-mixing processes for precision laser technology.展开更多
A high power continuous-wave single-frequency green fiber laser by second-harmonic generation of a Yb-doped fiber amplifier(YDFA)is developed.A linearly polarized single-mode fiber amplifier produces a 60 W infrared l...A high power continuous-wave single-frequency green fiber laser by second-harmonic generation of a Yb-doped fiber amplifier(YDFA)is developed.A linearly polarized single-mode fiber amplifier produces a 60 W infrared laser at 1064 nm with a 103 W incident diode pump laser at 976 nm,corresponding to an optical conversion efficiency of 58%.An external bow-tie enhancement cavity incorporating a noncritically phase-matched lithium triborate crystal is employed for second-harmonic generation.A 33.2 W laser at 532 nm is obtained with a 45 W incident 1064 nm fundamental laser,corresponding to a conversion efficiency of 74%.展开更多
This study analyzes the linewidth narrowing characteristics of free-space-running Brillouin lasers and investigates the approaches to achieve linewidth compression and power enhancement simultaneously.The results show...This study analyzes the linewidth narrowing characteristics of free-space-running Brillouin lasers and investigates the approaches to achieve linewidth compression and power enhancement simultaneously.The results show that the Stokes linewidth behavior in a free-space-running Brillouin laser cavity is determined by the phase diffusion of the pump and the technical noise of the system.Experimentally,a Stokes light output with a power of 22.5 W and a linewidth of 3.2 kHz was obtained at a coupling mirror reflectivity of 96%,which is nearly 2.5 times compressed compared with the linewidth of the pump(7.36 kHz).In addition,the theorical analysis shows that at a pump power of 60Wand a coupling mirror reflectivity of 96%,a Stokes output with a linewidth of 1.6 kHz and up to 80%optical conversion efficiency can be achieved by reducing the insertion loss of the intracavity.This study provides a promising technical route to achieve high-power ultra-narrow linewidth special wavelength laser radiations.展开更多
基金The work was partly supported by the National Natural Science Foundation of China(No.62075226).
文摘The phase summation effect in sum-frequency mixing process is utilized to avoid a nonlinearity obstacle in the power scaling of single-frequency visible or ultraviolet lasers.Two single-frequency fundamental lasers are spectrally broadened by phase modulation to suppress stimulated Brillouin scattering in fiber amplifier and achieve higher power.After sum-frequency mixing in a nonlinear optical crystal,the upconverted laser returns to single frequency due to phase summation,when the phase modulations on two fundamental lasers have a similar amplitude but opposite sign.The method was experimentally proved in a Raman fiber amplifier-based laser system,which generated a power-scalable sideband-free single-frequency 590 nm laser.The proposal manifests the importance of phase operation in wave-mixing processes for precision laser technology.
文摘A high power continuous-wave single-frequency green fiber laser by second-harmonic generation of a Yb-doped fiber amplifier(YDFA)is developed.A linearly polarized single-mode fiber amplifier produces a 60 W infrared laser at 1064 nm with a 103 W incident diode pump laser at 976 nm,corresponding to an optical conversion efficiency of 58%.An external bow-tie enhancement cavity incorporating a noncritically phase-matched lithium triborate crystal is employed for second-harmonic generation.A 33.2 W laser at 532 nm is obtained with a 45 W incident 1064 nm fundamental laser,corresponding to a conversion efficiency of 74%.
基金the National Natural Science Foundation of China(No.61927815)the Natural Science Foundation of Tianjin City(Nos.22JCYBJC01100 and 20JCZDJC00430)+4 种基金the Shijiazhuang Overseas Talents Introduction Project(No.20230004)the Program of State Key Laboratory of Quantum Optics and Quantum Optics Devices(No.KF202201)Funds for Basic Scientific Research of Hebei University of Technology(No.JBKYTD2201)D.J.acknowledges the support from the Postgraduate Innovation Ability Training Program of Hebei Province(No.CXZZBS2021030)R.P.M.acknowledges the support from the Asian Office of Aerospace Research and Development(AOARD).
文摘This study analyzes the linewidth narrowing characteristics of free-space-running Brillouin lasers and investigates the approaches to achieve linewidth compression and power enhancement simultaneously.The results show that the Stokes linewidth behavior in a free-space-running Brillouin laser cavity is determined by the phase diffusion of the pump and the technical noise of the system.Experimentally,a Stokes light output with a power of 22.5 W and a linewidth of 3.2 kHz was obtained at a coupling mirror reflectivity of 96%,which is nearly 2.5 times compressed compared with the linewidth of the pump(7.36 kHz).In addition,the theorical analysis shows that at a pump power of 60Wand a coupling mirror reflectivity of 96%,a Stokes output with a linewidth of 1.6 kHz and up to 80%optical conversion efficiency can be achieved by reducing the insertion loss of the intracavity.This study provides a promising technical route to achieve high-power ultra-narrow linewidth special wavelength laser radiations.
