The Research Of Iintra-cavity Pumped Dual-wavelength Laser

Nowadays,dual-wavelength lasers have extensive applications in a variety of areas,such as laser communication,medical instrumentation,precision laser spectroscopy,holography,radar,and nonlinear optical mixer research.Due to the difference between the emission cross-sections of two transition lines,the gain competition will be produced by conflicting with each other which means it is hard to obtain efficiently and stable dual-wavelength output,using single crystal to achieve the dual-wavelength laser output is a commonly method.So that it is difficult to obtain highly efficient and stable dual-wavelength laser output.And then,we decided to adopt intra-cavity pumping to achieve dual-wavelength output which could absolutely avoided gain competition.Therefore,we engaged in the intra-cavity theoretical and experimental research.1.According to study the principle of intra-cavity pumping which include indirect pumping,direct pumping,four level laser,quasi-three level laser.And then,we established the theory model which can describes the principle and output characteristics of intra-cavity pumped dual-wavelength lasers.On the basis of the theory model,the transmittance of output mirror has been optimized.2.Simulation of intra-cavity pumped dual-wavelength lasers propagation process by using ABCD matrix.On the basis of theory simulation,the resonant cavity design of intra-cavity pumping dual-wavelength laser has been obtained.Thus,we have determined the realization of the resonator parameters,and simulated the waist size and location in the cavity which laid the foundation for the experiment.3.Experiments have been carried out by intra-cavity pumped dual-wavelength lasers theory:(1)We adopt a compact intra-cavity pumped structure of Nd:YAG and Nd:YVO4 crystals to develop an efficient dual-wavelength laser that operates at 946 nm and 1064 nm.A 808 nm laser diode is used to pumping the Nd:YAG crystal,which emits at 946 nm,and the Nd:YVO4 crystal,which emits at 1064 nm,is intra-cavity pumped at 946 nm.A total output power of 4W at the dual-wavelengths is achieved at an incident pump power of 30.5W,where the individual output powers for the 946 nm and 1064 nm emissions are 1.1 W and 2.9W,respectively.The output power at 1064 nm can be adjusted from 1.0W–2.9W by varying the separation between the two crystals.(2)After that,we use the direct pumping source at 879 nm instead of the 808 nm laser diode to continue our research.We adopt a compact intra-cavity pumped structure of Nd:GdVO4 and Nd:YVO4 crystals to develop an efficient dual-wavelength laser that operates at 912 nm and 1064 nm,which could reduce the thermal effort of the device.As we know,the first crystal Nd:GdVO4 was pumped directly into the emitting level by a laser diode at 879 nm,it is the first to use direct pumping to achieve the dual-wavelength output in our country.When the absorption of pump is 8.55 W,we obtain the total output power of 1.65 W at dual-wavelengths,where the individual output power for the 912 nm and 1064 nm emissions are 0.58 W and 1.07 W,respectively.