Research On Diode-Pumped Near-Infrared Solid State Ultrafast Laser

The research on ultrafast lasers has been a hot topic in the field of lasers,as ultrafast lasers are increasingly used in military,industrial and medical fields.The pursuit of ultrafast lasers has moved from short pulses to high power and other new indicators.High-brightness diode-pumped all-solid-state lasers are particularly favored because of their compact structure,low cost,and high efficiency.The main task of this paper is to develop the laser diode-pumped all-solid-state lasers in the near-infrared wavelength range.The main contents of this paper's work are as follows:1.The continuous wave and semiconducting saturable absorber mirrors?SESAMs?passive mode-locking properties of Yb:GYSO crystal were experimentally studied.Five-mirrors folding cavity were used,the 1052 nm continuous wave with a maximum output power of334 mW was obtained.The mode-locked laser with a center wavelength of 1050 nm was achieved by SESAM passive mode-locking.The output pulses have a spectrum bandwidth of 1.8 nm,a pulse duration was 787 fs and a repetition rate of 78 MHz.2.The LD-pumped Kerr-lens mode-locked operation was obtained with a 15 at.%Yb:LuAG laser transparent ceramic was using as the gain medium.The center wavelength of the mode-locked laser is 1046 nm with a full width at half maximum of 16.2 nm.The pulse duration is 159 fs,the repetition rate is 121 MHz,and a maximum output power of121 mW was achieved.The 16.2 nm mode-locked laser spectrum bandwidth theoretically supports ultrashort pulses with a Fourier transform limit of 80 fs,which indicating the potential of Yb:LuAG laser transparent ceramics to achieve ultra-short femtosecond laser pulses^[1].3.The high repetition rate all-solid-state laser was experimentally studied.A single-mode LD was used as the pump source.Mode-locking operation was achieved in the Yb:LYSO laser by Kerr-lens mode-locking,and 58 fs pulse duration was obtained,which is the shortest pulse duration for the Yb:LYSO laser.The spectrum bandwidth of the mode-locked laser is 21.3 nm with the center wavelength at 1063 nm,The repetition rate of the laser is 207 MHz.A maximum output power of 56 mW was obtained when 900 mW pump power was provided,and the corresponding optical to optical slope efficiency is6.2%.Compared with the previous work?Opt.Express 22,19040?2014?.?,this experiment not only improved the repetition frequency of pulses,but also shortened the pulse duration.4.The performance of YAG/Nd:LuAG/YAG laser ceramics with a composite structure was studied.The continuous wave properties of different doping concentrations and different Nd:LuAG thicknesses were experimentally studied.When the pump laser vertically through the sandwich composite structure,the output power of continuous wave has a slope efficiency of 9.1%,the maximum output power is 1.1 W;when the pump laser along the sandwich middle layer to pump the ceramic,and the maximum output power is 0.1 W.