12th International Conference on Optics, Photonics & Lasers
Technical Institute of Physics and Chemistry-CAS, China
Title: High power high-repetition-rate microsecond pulse sodium beacon laser
Biography: Yong Bo
Sodium laser guide star is generated by resonant scattering of a 589nm laser with sodium atoms in the upper atmosphere of the altitude of 80-105 km. As a beacon with the sodium laser guide star, an adaptive optics system can correct the wavefront aberration due to atmospheric turbulence and improve greatly the large ground telescope resolving power. In the letter, a high power high-repetition-rate microsecond pulse sodium beacon laser prototype was developed. Th e sodium beacon laser is based on sum-frequency mixing between the 1064 nm and 1319 nm beams in a LBO crystal. Both the 1064 nm and 1319 nm lasers are produced from diode-side-pumped Nd:YAG master oscillator power amplifi er (MOPA) laser systems. At the repetition rate of 500 Hz and pulse width of about 120 μs, the average output power of 65 W is achieved with the wavelength of 589.159nm. Th e beam quality factor of M2 is 1.4 and the linewidth is about 0.3 GHz. By using the sodium beacon laser prototype, a bright sodium laser guide star with a photon return of 1820 photons.cm-2.s-1 was generated and observed with the projected power of 32W by the telescope in Xinglong site. What is more, a high resolution image of a star with the sodium laser guide star generated was obtained by the 1.8m telescope with the adaptive optics in Lijiang site.