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Investigation Of LD-pumped Dual-frequency Nd:YAG Laser Technique

Posted on:2006-11-05Degree:MasterType:Thesis
Country:ChinaCandidate:Y LiuFull Text:PDF
GTID:2168360152975431Subject:Measuring and Testing Technology and Instruments
Abstract/Summary:PDF Full Text Request
Dual-frequency laser plays an extremely important role in interferometric measurement of absolute-distance. Because the measurement approach measures the distance rather than the displacement, it doesn't need precise guide rail, but it requires a dual-frequency laser source with its frequency-difference as large as possible to obtain smaller synthetic wavelength, so as to improve measurement accuracy. As a result, investigating the dual-frequency laser technique is of great significance.In order to find a new approach to acquire tunable dual-frequency laser output, a laser-diode (LD) end-pumped dual-frequency Nd:YAG laser technique is analyzed theoretically and investigated experimentally in the thesis. Five contents are mainly included as follows. First, the fundamental theory of LD-pumped solid-state laser (DPSSL) is analyzed. By means of the rate equation of four-energy-level DPSSL, the theoretical analysis and investigation of DPSSL's working characteristics are conducted. Second, the makeup and the design principle of LD-pumped Nd:YAG laser are introduced. The corresponding experimental system is established and its output characteristics are investigated. Third, a current supply for LD is designed and developed, which continuously adjustable output current from zero to three amperescan be achieved, corresponding to the stability of time is better 0.1% within five hours. It is successfully applied to the LD-pumped Nd:YAG laser system. Fourth, the laser longitudinal mode splitting theory based on intracavity birefringence effect is analyzed. One quarter-wave plate and two quarter-wave plates being inserted in LD-pumped Nd:YAG laser resonant cavity, respectively, the Nd:YAG laser longitudinal mode splitting and the oscillating output of the tunable dual-frequency laser are investigated experimentally. When a quarter-wave plate is inserted in the cavity, with the end surface of the quarter-wave plate normal to the laser beam, the laser magnitude of the longitudinal mode splitting is just equal to one half of the longitudinal mode interval; When the other same quarter-wave plate is placed in the cavity in the same manner as before, the splitting magnitude is tunable over a whole range of one longitudinal mode intervel by means of the angle between the fast (or the slow) axes of both quarter-wave plates changed in a range of 0 ~ 90 degrees, and the oscillating output of tunable dual-frequency laser is realized. Fifth, on the basis of analyzing the theory of selecting single longitudinal mode by birefringent filter, a novel scheme of LD-pumped intracavity frequency-doubled Nd:YAG/KTP dual-frequency green laser is proposed. Feasible analyses and preliminary experimental investigations are carried out, and the simultaneous outputs of the green laser at 532-nm wavelength in the two cavities can be achieved.
Keywords/Search Tags:dual-frequency laser, Nd:YAG crystal, LD pumping, birefringence effect, quarter-wave plate
PDF Full Text Request
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