The Characteristics Studies Of RTP And KTP Ramanlaser

With the development of the technology,laser has been widely used in the files of industry,national defense,biology,medical.Usually,different wavelength laser sources are required in different fileds.So new wavelength laser generation has been a research hotspot.Nonlinear optical frequency conversion technique is a reliable method to obtain a new wavelength laser.Among them,stimulated Raman scattering(SRS)belongs to a third-order nonlinear effect,with advantages of high conversion efficiency,no need for phase matching.Beam clean-up,and so on.By selecting different pump sources and Raman mediums,the Stokes wavelength can be spread from ultraviolet to near infrared.Compared with gas and liquid Raman media,solid Raman media has the advantages of high ionic concentration,small volume,high Raman gain,good thermal conductivity,good optical and mechanical properties.Rencently,all solid Raman lasers using crystals as Raman media have been extensively studied and used in the fileds of defense and military,information and communication,medical cosmetology and industrial manufacturing.RbTiOPO4 and KTiOPO4 are excellent nonlinear optical crystals,with advantages of large second-order non-linear optical coefficient,wide transmission range and high damage threshold.These excellent properties make them be widely used in laser frequency doubling and optical parametric oscillators.In recent years,they also have been found to be excellent Raman crystals with high third-order non-linearity.They also can be used in solid-state Raman lasers.In this paper,we studied the LD end-pumped actively Q-switch Nd:YAG/RTP Raman laser and passively Q-switch Nd:YAG/RTP Raman laser at 1.1 ?m.Then we studied RTP eye-safe Raman laser 1.5 ?m by using an Nd:YAG as gain medium,a RTP as Raman medium.Finally,an LD end-pumped actively Q-switch Nd:YAG/KTP intracavity Raman laser.The first order and second order stokes of KTP Raman laser were achieved,respectively.The specific research contents are as follows:1.The characteristics of an LD end-pumped actively Q-switched Nd:YAG/RTP Raman laser were studied by using an Nd:YAG as gain medium and a RTP crystal as the Raman medium.When the pump power was 11.7 W and the pulse repetition frequency was 15 kHz,the obtained 1095 nm laser output power was 402 mW.The corresponding conversion efficiency was 3.5%.2.An LD end-pumped passively Q-switched Nd:YAG/RTP Raman laser were realized.A Cr4+:YAG saturable absorber with initial transimission of 95%was used as the passively Q-switch.A 232 mW 1095 nm laser was obtained at an incident pump power of 7.9 W.The corresponding conversion efficiency was 2.9%.3.The RTP eye-safe Raman laser at 1495 nm were realized.A dual-end diffusion-bonded YVO4-Nd:YVO4-YVO4 crystal was employed as the laser medium to generate 1.34 ?m laser radiation,and an RTP crystal as the Raman medium to enable the frequency conversion.With an incident pump power of 10.4 W,an average output power of 502 mW was obtained at a pulse repetition rate of 15 kHz,corresponding to a conversion efficiency of 4.8%.4.With a Nd:YAG crystal as the gain medium and a KTP crystal as the Raman medium,the first-order Stokes were achieved.When the incident pump power was 13.17 W and the pulse repetition frequency was 40 kHz,a 2.14 W 1095.5 nm laser was obtained with a pulse width of 5.5 ns.The corresponding conversion efficiency was 4.8%.A 966 mW second order Stokes was obtained with an incident pump power of 12.28 W and a pulse repetition frequency of 30 kHz.The corresponding conversion efficiency was 7.8%.The main innovations of this paper are as follows:1.For the first time,the LD end-pumped actively Q-switched Nd:YVO4/RTP eye-safe Raman laser were realized.With an incident pump power of 10.4 W and a pulse repetition frequency of 15 kHz,a 502 mW 1495 nm laser was obtained.The corresponding conversion efficiency was 4.8%.2.The LD end-pumped actively Q-switch Nd:YAG/RTP intracavity Raman laser is realized.At an incident pump power of 11.7 W and a pulse repetition frequency of 15 kHz,402 mW 1095 nm laser was obtained,the corresponding conversion efficiency was 3.5%.The LD end-pumped passively Q-switch Nd:YAG/RTP intracavity Raman laser is realized.At an incident pump power of 7.9 W and a saturable absorber's initial transimission of 95%,a 232 mW 1095 nm laser was obtained with a corresponding conversion efficiency of 2.9%.3.The first order and second order stokes of KTP Raman laser were studied,respectively.A 2.14 W 1095.5 nm first order Stokes laser was obtained with a pulse width of 5.5 ns and a conversion efficiency of 4.8%.A 966 mW second order Stokes laser was obtained with an a pulse repetition frequency of 30 kHz and a conversion efficiency was 7.8%.