Characterization Of New Type Laser Crystals

The optical waveguide is an important structure in integrated optics,and waveguiding lasers are of great significance to the practical application in the miniaturized solid-state lasers in optoelectronics.For those potential application,the miniaturization of lasers into monolithic devices is becoming currently the subject of considerable research interests.From this point of view,the optical waveguide configuration design is of particular importance in the field of optoelectronics.Ion implantation is an effective method to fabricate waveguides in optical materials and to improve the performance of laser crystals.Based on ion irradiation,the optical properties of Yb:Lu AG,Yb:KGW,Yb:YAP,Nd:YAP laser crystals are characterized.The main content of this thesis is as follows:Yb:Lu AG crystals are irradiated with Si ions at an energy of 4.5 Me V,fluences of1.0×10¹⁴,5.0×10¹⁴,and 1.0×10¹⁵cm^-2.The prism coupling technique is used to investigate the dark modes of the implanted Yb:Lu AG crystal.The results show that the typical barrier-type optical waveguide structures are formed near the surface in Si-implanted Yb:Lu AG.The RCM method is used to reconstruct the refractive index profiles and to simulate the transverse-electric（TE）and transverse-magnetic（TM）field intensity distribution.The dependence of TE and TM field strengthen with depth is also analyzed.The photoluminecence results show that the original fluorent performance can be well retained in the implanted Yb:Lu AG crystals.Yb:KGW crystals are irradiated with C ions at an energy of 6.0 Me V and fluences of 4.5×10¹⁵ cm^-2.The guding mode measurements demonstrate that a barrier-type optical waveguide structure is formed near the surface of the Yb:KGW crystal.Under an excitation at 930 nm with Xenon lamp,the photoluminescence results show that both the near-infrared emission intensity and fluorescence emission cross-sectional area of Yb:KGW are significantly enhanced after C ion implantation with an energy of 6.0Me V and fluences of 4.5×10¹⁵ cm^-2.Si ions with an energy of 4.5 Me V,fluences of 5×10¹⁴ and 1×10¹⁵ cm^-2 are implanted into Yb:YAP crystals.The prism coupling results show that a barrier-type optical waveguide structures are formed in irradiated samples.The photoluminescence spectrum is characterized under the pump of 930 nm with Xenon lamp,and the results illustrate that the near-infrared emission can be effectively improved in Si-implanted Yb:YAP crystals.Si ions with an energy of 4.5 Me V,fluences of 5×10¹⁴ and 1×10¹⁵ cm^-2 are implanted into Nd:YAP crystals.The prism-coupling method is used to observe guiding modes at a wavelength of 633 nm laser.The results show that a barrier-type optical waveguide structures are confirmed in the irradiated Nd:YAP samples.Under the excitation of 808 nm laser,the up-conversion and near-infrared luminescence emission of the irradiated samples are investigated.The corresponding upconversion mechanisms are also discussed.