The laser properties of 1064 nm pulse laser is investigated by optimizing mirror curvatures of resonant cavity. When the curvature of the laser rod pumping surface is -2000mm, the laser operating stability region of different mirror curvature radius is simulated, the simulation results show that the fundamental mode radius is increasing with a decrease in radius of mirror curvature. The two mirror curvatures are finally optimized to 1300 mm, 1500 mm, 3000 mm and 4000 mm, the fundamental mode radius is 0.91 mm, 0.71 mm, 0.53 mm, 0.50 mm, respectively. The experiments results show that the pump end face of the crystal rod is damaged under pumping energy of 451W when the radius of curvature is 4000 mm, and the maximum static state energy is 77.5W under the pump energy of 415W. The pump end face of the crystal rod is damaged under pumping energy of 470W when the radius of curvature is 3000 mm, and the maximum static state energy is 85.2W under the pump energy of 451W. The dynamic state energy with the mirror curvature of 1500 mm is larger than that with the mirror curvature of 1300 mm under the same pump energy and the dynamic state energy is 86.6 mm and 89.5 under the pump energy of 489W with the curvature of the output coupled mirror of 1300 mm and 1500 mm. The damage of the pump end face of the crystal rod is not appear with the curvature of the output coupled mirror of 1500 mm while pumping energy is up to 541W, and the static state energy is 154.2 mJ and the dynamic state energy is 92.4 mJ under the pump energy of 541 mJ corresponding to the dynamic static ratio of 60%. Optimization of curvatures radius of cavity mirrors is carried out to reduce the power density in cavity, which can provide an effective technical means for obtaining high-energy end-pumped Q-switched laser output.
High energy 1064 nm Q-switched laser output is obtained by LD vertical array end pumping Nd:YAG. For different divergence angles of fast axis and slow axis of LD array, aspheric lens and the glass rod is used for beam shaping of LD array. The results show that light intensity distribution of output laser is very sensitive to the structure of the beam shaping system, which can be controlled by adjusting the spatial position of pumping, such as the distance between the aspheric lens and the face of the glass rod, and the approximate Gaussian beam was obtained without damage. When the distance between the aspheric lens pair and the face of the glass rod is 16mm, a 1064 nm Q-switched laser with single pulse energy of 60.4 mJ under the pump energy of 489 mJ, corresponding to optical conversion efficiency of 12.4%.
High energy 1064 nmQ-switched laser output is obtained by LD vertical array end pumpingNd:YAG. For different divergence angles of fast axis and slow axis of LD array, aspheric lens and the glass rodis used for beam shaping of LD array. The results show that light intensity distribution of output laser is very sensitive to the structure of the beam shaping system, which can be controlled by adjusting the spatial position of pumping, such as the distance between the aspheric lens and the face of the glass rod, and the approximate Gaussian beam was obtained without damage. When the distance between the aspheric lens pair and the face of the glass rod is 16mm, a 1064 nm Q-switched laser with single pulse energy of 60.4 mJ under the pump energy of 489 mJ, corresponding to optical conversion efficiency of 12.4%.
When using large ground-based telescopes to observe celestial bodies, due to the influence of atmospheric turbulence, the images obtained are blurred and the resolution is limited. By emitting a yellow 589 nm laser into the sky, the sodium atom in the air layer at a height of 90 km is excited to form a sodium guide star. The adaptive optical technology containing the sodium guide star can be used to correct the image distortion, so that the telescope can reach the theoretical diffraction limit resolution. The 589 nm laser is called sodium guide star laser, which is the key component. The sum frequency of 1064 nm and 1319 nm spectral lines of Nd:YAG crystal in nonlinear medium can produce 589 nm yellow laser, which is one of the main ways to obtain 589 nm sodium guide star laser. Under the ideal monochromatic uniform plane wave and slowly varying amplitude approximation, the sum frequency process can be described by three wave coupling equations. The three wave coupling equations are numerically simulated by the improved Euler method. In the simulation process, the sum frequency process is approximated as follows: the beam radius follows the propagation law of Gaussian beam, the sum frequency process meets the phase matching, and only the sum frequency nonlinear effect exists in the crystal. Specifically, the 589 nm sum frequency process of 1064 nm and 1319 nm laser through LBO crystal is numerically simulated. The relationship between the sum frequency efficiency and the focusing parameters, crystal length, fundamental frequency power ratio and other parameters is studied respectively, and the optimal sum frequency parameters are obtained under given conditions.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.