Pulsed Laser Research Based On Gold Nanorod Saturable Absorbers

Passively Q-Switched laser is widely researched due to its character that we don't need to plus electronic tuning Q switch device,just place saturable absorber into the laser cavity.Saturated absorber can absorb the light at a specific wavelength,and output the pulse laser.In this thesis we mainly introduce the pulse laser based on a new type of saturated absorber-gold nanorods.In the process of study,we mainly use Nd: YSAG crystal,Nd: LGGG crystal,Nd: YVO₄ crystal as gain medium and the 808 nm LD pump sources,then we get the pulse laser of 1.06 ?m.As an important part of the passive tuning Q laser,the development of saturable absorber has been brought to the attention of the researchers.Ideal saturable absorber should have fast corresponding time,wide absorption bandwidth,large third order nonlinear coefficient,low cost,and so on.1.In this thesis,we introduce the development course of laser,the key technology of passive tuning Q.We introduce the working principle of laser and the basic principle of Q technology.2.In this thesis,we mainly introduce several kinds of laser crystal,and the operating characteristics of Nd: YSAG crystals,Nd: LGGG crystal,Nd: YVO₄ crystal.The advantages and disadvantages of each crystal are described.And we also focus on the advantage of Nd: YSAG crystal relative to the Nd: YVO₄ crystal as gain medium.3.Saturated absorbers are introduced in this thesis,including traditional saturable absorber Cr4 +: YAG,semiconductor saturable absorption mirror and a new type of saturable absorber-graphene and carbon nanotubes.The operating characteristics of nanomaterials and gold nanorods are also introduced.4.In this thesis,we use the gold nanorods of length to diameter ratio of 6.75 as a saturable absorber,study the output characteristics of Nd: YSAG laser,Nd: LGGG laser,Nd: YVO₄ laser,and then 1.06 ?m laser output is obtained.The laser pulse frequency is relatively high and the peak power is large.5.The main innovation points: For the first time,we put gold nanorods in the solid state laser as a saturable absorber,and get the high frequency,large power laser output of 1.06 ?m.We study the characteristics of the Nd: YSAG crystals,meanwhile.