Investigation On Two Micron Pulse Fiber Laser And Laser Direct Writing Nickel-Doped Oxyfluoride Glass Ceramic Waveguide Devices

Since the 1960s,the development of laser has been changing with each passing day,and its application has involved all aspects of human society.The near infrared band is widely used in processing,medical treatment,military and other fields.Therefore,the research on this band laser is of great significance,this paper devoted to the research of two micron pulse fiber laser and the application of femtosecond laser direct writing optical waveguide devices.It mainly includes the generation of 2-micron Q-switched laser using tungsten-molybdenum doped transition metal sulfide alloy material,the transmission characteristics when the 1568-nm CW laser was directed into a novel Ni-doped oxyfluoride glass-ceramic waveguide and beam splitter written directly by laser,and the experimental study of 1.7-micron laser output using bulk Ni-doped fluoride glass-ceramic as gain medium.Its main work includes the following:1.In the Tm-doped all fiber laser,we used 793 nm diode laser as pump laser,and the Mo_0.8W_0.2S₂ as saturable absorber.At the pump power of 2.17 W,we achieved the output of stable Q-switched pulse.The central wavelength of the pulse was 2027 nm.And with the change of pump power,the results show that,the value of repetition frequency changed from11.9 kHz to 15.7 kHz,the energy of single pulse increases from 278 nJ to 507 nJ,and the pulse width decreases from 17.1?s to 11.7?s.And we got the maximum output power of7.4 mW.2.The KZnF₃:Ni²⁺oxyfluoride glass-ceramic material waveguide written by femtosecond laser is used to test the loss when the laser of 1568 nm transfer inside.It is found that the minimum transmission loss is 1.68 dB/cm when the laser with the single pulse energy of 2.2?J and the scanning rate of 100?m/s.What's more,the refractive index change of?n=8.8×10^-4 of the waveguide is obtained with the help of numerical aperture method.3.A continuous wave laser with a wavelength of 1568 nm is used to transmit in a KZnF₃:Ni²⁺Oxyfluoride glass ceramic splitter written by femtosecond laser and measured its transmission characteristics.The beam splitter is a single line waveguide structure,and the single pulse energy of machined femtosecond laser is 2.2?J.When the angle of the beam splitters is 1°,2°and 3°,the total loss of the Y beam splitter structure is 2.79 dB,4.84 dB,8.58 dB,respectively.And the corresponding output end splitting ratio is 0.5:0.5,0.49:0.51and 0.47:0.53.4.The simple simulation of beam splitter transmission in Oxyfluoride glass ceramics is carried out by BPM software.And we still used the 1568 nm continue laser as the testing laser.In the simulation results,it is found that with the increase of beam splitting angle of Y-beam splitter,the value of the ratio of output power from two branches of beam splitter to input is smaller,and the loss of laser energy loss from the two branches became larger.That is,the smaller the ratio of output power to input power of beam splitter is,the larger the loss is.But in the simulation process,it is also found that when the angle of beam splitter is smaller to a certain range,the lasers from the two branches of the beam splitter will affect each other,then the function of the beam splitter can not be used normally.5.An experimental study of solid state laser based on flat concave resonator is carried out.and the KZnF₃:Ni²⁺Oxyfluoride glass ceramic material is used as gain medium.During the experiment,the laser with the wavelength of 405 nm was used to pump the cavity,and a dichroic mirror and a concave OC were used to form the plano-concave resonator,and the KZnF₃:Ni²⁺Oxyfluoride glass ceramic lump material acts as gain medium between the dichroic mirror and the concave OC.In the end,the experiment failed to get the expected1.7 m laser,because it was found that the damage threshold of the material was lower than its threshold of laser emission,which caused the material to be damaged under the high-energy laser before it generated the laser.