Aperiodic Poled Lithium Niobate Electro-optic Bragg Deflector as an Efficient Laser Q-switch in a Dual-wavelength Solid-State Laser

• Main Authors: Quan-Hsiang Tseng, 曾冠翔
• Other Authors: Yen -Hung Chen
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/36512071132822103188

碩士 === 國立中央大學 === 光電科學研究所 === 99 === Bragg condition is very sensitive to incident wavelength. With this characteristic, we can diffract wavelength with appropriate Bragg structure. In this letter, we first design an aperiodic structure with the help of simulated anneal algorism which compensates reciprocal vectors of dual wavelength emitted in Nd doped solid state laser system. Lithium Niobate is a great electro-optic crystal. With the technics of high electric field poled, we can generate the structure we calculate previously on LN crystal. Thus, a 40 mm long, 5 mm in width and thickness of 0.5 mm aperiodic poled Lithium Niobate Bragg diffraction device is fabricated successfully. In experiment, we measured the high diffraction efficiency both on 1064 nm and 1342 nm, 93.5% and 92.5% respectively, at 120 volt applied voltage. Furthermore, we put our chip into the Nd:YVO4 slid sate laser system and applied a periodic electric field to the chip, we can turn it into a cavity Q-switch device. With the sum frequency crystal BIBO, we can generate narrow and high peak power 593 nm output from dual emission wavelength of Nd 1064 nm and 1342 nm. In results, the yellow-orange light output with the pulse width of 9.7 ns and peak power of 167 W under 8.142 W of Nd absorption power.