The Study Of All Solid-state Laser On Blue Laser Pumped Pr:YLF Directly Obtaining Visible Laser

The wavelength at 600-650 nm laser is particularly useful in many fields,such as laser projector,laser color displays,lithographic printing,laser communication.The stable dual-wavelength laser is achieved at visible region usually by frequency-doubling and sum-frequency.Compared with the direct generation,the disadvantage is obvious that it needs one or two nonlinear optical frequency conversion process and the conversion efficiency is usually very low.The requirement of continuous wave?CW?orange light sources is growing steadily,and scientists begin to look for a novel laser which can emit the yellow-orange spectrum directly.Blue laser diode-pumped Pr³⁺ doped laser materials is an efficient and simple method which can obtaining the visible region laser.Therefore,The blue laser diode-pumped Pr³⁺:YLF laser which directly obtaining visible laser is investigated in this paper,the main content of this paper as follows.1.The characteristics of Pr³⁺:YLF crystal with different polarization direction have been measured,and obtained relative parameters of laser crystal.Then the model of Pr³⁺ laser is established with the theory of four-level rate equation,and the influence of the laser output characteristics to the transmittance of output mirror and spot radius of the pump beam is simulated.On the basis of theoretical analysis,the transmittance of output mirror is optimized.2.A method which inserting an F-P etalon in the cavity to select wavelength is analyzed.By choosing the appropriate thickness and the angle of the etalon,the transmittance between different wavelengths can be controlled.Accordingly,the specific wavelength selecting can be realized by controlling the loss among different wavelengths.The influence of the threshold value with the tilt angle and the thickness of F-P etalon is derived to select the optimized thickness and tilt angle,finally achieve the multi-wavelength output,it provides a theoretical basis to guide the experiment.3.With the theoretic analysis in the previous,the blue laser diode-pumped Pr³⁺:YLF laser which directly obtaining orange red laser is investigated experimentally:?1?The laser diode is integrated with a focusing lens group for re-imaging the pump beam,the characteristics of blue laser diode with different output power have been measured,and the absorption efficiency of the laser crystal with different polarization direction is calculated;?2?In the experiment,the laser crystal with different polarization and the output mirror with different radius of curvature and transmittance is analyzed.And obtain the 639 nm red laser output with the maximum output power is 492 mW,and the 607 nm orange laser output with the maximum output power is 177 mW.The dual-pumped Pr³⁺:YLF laser directly obtaining orange laser is investigated experimentally,the V-type cavity is used in the experiment,and the maximum output power of 607 nm laser with 58 mW is obtained;?3?Through adjusting the etalon,the dual-wavelength at 607 nm 639nm and the three-wavelength at 604 nm 607nm and 639 nm is achieved,which output power is up to 30 mW and 25 mW,the validity of theoretical analysis is verified by experiment.