The Study Of Novel All Solid State Near-infrared Short Pulsed Lasers

All solid-state lasers have the advantages of high conversion efficiency,stable output laser performance,good beam quality,high structure integration and convenient handling,and have always been a hotspot in laser field.Among them,the short pulsed lasers realized by Q-switched technique and mode-locking technology have the advantages of high peak power,easy control of pulse energy and high repetition frequency,which can meet the practical needs of many applications.In this paper,novel wavelength Nd:YAG ceramic short pulse laser,novel mixed crystal short pulse laser and novel saturable absorber short pulse laser are studied based on Q-switched technique and mode-locking technique respectively.The main contents of this paper are as follows:In the 2rd chapter:We study the high-power continuous and passive Q-switched lasers with 1052 nm single-wavelength Nd:YAG ceramics.The maximum output power of continuous laser is 6.1 W,which is the highest output power of 1052 nm single wavelength,and the light conversion efficiency and slope efficiency are 26.2%and 30.0%.Using the Cr4+:YAG as a saturable absorber,the narrowest pulse width of 1052 nm single-wavelength Nd:YAG ceramic passive Q-switched short pulse laser is 15.36 ns,the maximum output power is 3.95 W,and the repetition frequency is 84 kHz.The 1357nm single-wavelength continuous and passive Q-switched short pulse lasers of Nd:YAG ceramics were studied.The maximum output power of continuous operation is 2.4 W,the optical conversion efficiency and slope efficiency are 16.2%and 18.6%,respectively.Using V3+;YAG as saturable absorber,the maximum output power of the passive Q-switched pulsed laser is 628 mW,the pulse width is 20 ns,and the repetition frequency is 15 kHz.1.4 ?m human eye-safety band Nd:YAG ceramic passive mode-locking is realized.The maximum average power of the laser pulse is 842 mW.The corresponding light conversion efficiency is 7.45%,the pulse width is 17.7 ps,and the center wavelength is 1443 nm with the line width is 0.21 nm.In the 3th chapter:The characteristics of continuous wave Nd:GYAG mixed crystal laser are studied,and the continuous laser with the maximum output power is 1.6 W.The corresponding light conversion efficiency and slope efficiency are 41%and 51.6%.The central wavelength is 1064.4 nm.The output characteristics of Z-type and W-type passive mode-locked ultrashort pulsed laser are studied respectively.The width of the pulse is 11.1 ps,the maximum output power is 480 mW and 210 mW respectively.The short pulsed laser performance of Nd:GYSO crystal is studied with a maximum output power of 1.5 W.The corresponding pulse width and repetition frequency are 87.7 ns and 4 kHz,respectively.The maximum output power of 1.5 W is obtained,and the Nd:GYSO crystal passive mode-locked ultrashort pulsed laser output is studied.A Z-type laser resonator was designed to achieve a 5 ps 1074 nm ultrashort pulse laser with a peak power of approximately 1 kW.In the 4th chapter:We studied the Nd:YSAG mixed crystal dual-wavelength passive mode-locked lasers.The maximum average output power is 470 mW,the two central wavelengths are 1060.8 nm and 1063.2 nm,and the autocorrelation waveform of the dual-wavelength laser is analyzed.The pulse width of the beat pulse is about 800 fs,the time interval is about 1.5 ps,and the pulse width of the autocorrelation envelope is about 3.8 ps.The femtosecond and dual-wavelength synchronous CWML lasers of Yb:YCOB mixed crystalwere studied.Without the dispersion compensation device,the femtosecond ultrashort pulse laser output of Yb:YCOB mixed crystal with 328 fs was realized.The center wavelength of the pulsed laser was 1038 nm,and the splitting of the spectrum peak was found.In the resonator,two GTI with-300 fs2 dispersion compensation were added to obtain the dual-wavelength synchronous laser.The highest average output power was about 240 mW.The two central wavelengths were 1041.6 nm and 1044.6 nm.A stable dual-wavelength mode-locked pulse laser interference pattern was obtained.In the 5th chapter:We studied the Nd:GAGG mixed crystal passive Q-switched short pulse laser with gold nanorods saturable absorber.The saturable absorbers were successfully grown by seed growth method.The optical properties were characterized.The results showed that the modulation depth,non-saturation loss and saturation energy density were 9%,50%,0.022 mW/cm2.By using Nd:GAGG as laser gain medium,the characteristics of passive Q-switched short pulsed lasers at 1061 nm and 1106 nm were studied.The Nd:YV04 mode-locked lasers with MoS₂ saturable absorbers were studied.The MoS₂ saturable absorber was fabricated successfully,and the optical properties of the elements were characterized.The modulation depth and saturation fluence were 7%and 847 nJ/m2,respectively.The effect of MoS₂ saturable absorber on the mode-locked pulsed laser was studied by using Nd:YV04 as laser gain medium,the highest output high power is 89 mW,pulse width is 12.7 ps.The main innovations are:1.For the first time,the 1357 nm passive Q-switched short pulsed laser of Nd:YAG transparent ceramic is realized.The maximum output power is 628 mW,the corresponding pulse width is 20 ns and the repetition frequency is 15 kHz.2.For the first time,we achieved an 1.4 ?m human eye-safety band passive mode-locked picosecond pulse laser output.The maximum average power of the output mode pulse is 842 mW,the pulse width is 17.7 ps.and the center wavelength is 1443 nm.3.For the first time,the output characteristics of Nd:GYAG mixed crystal Z-type and W-type passive mode-locked ultrashort pulsed lasers are realized.The width of the pulse is 11.1 ps and the maximum output power is 480 mW and 210 mW respectively.4.The Nd:GYSO crystal is used to achieve dual-wavelength Q-switched laser for the first time,the maximum output power of 1.5 W.The Nd:GYSO crystal 5 ps passive mode-locked ultrashort pulse laser is realized.5.The dual-wavelength synchronous output of the Yb:YCOB crystal is realized.The maximum output power is 470 mW,the two central wavelengths are 1060.8 nm and 1063.2 nm,and the autocorrelation waveform of the output dual-wavelength laser is carried out for the first time.6.The dual-wavelength synchronous output of the Yb:YCOB crystal is 240 mW,and the two central wavelengths are 1041.6 nm and 1044.6 nm.7.The Nd:GAGG mixed crystal passive Q-swicthed short pulse lasers at 1061 nm and 1106 nm with gold nanorods saturable absorber were realized.8.A MoS₂ saturable absorber Nd:YVO₄ mode-locked laser was realized with a pulse width of 12.7 ps and a maximum output of 89 mW.