Study On Fundamental Mode And Thermal Dynamic Stable Laser At 447nm

Nowadays, the technologys of all-solid-state red light/green light laser are getting more mature. But the development of the all-solid-state blue light laser is relatively backward (especially 447nm blue light laser). The chief reason is that we must use third harmonic generation to get the 447nm blue light laser. This means its optical system will be more complicated and it will be more difficult to materialize, also, its output power will lower than red/green light laser which is generated by frequency-doubling. So how to increase the power is still a main topic in the field of 447nm laser study, and the study of other properties are relatively insufficient. Therefore in this paper, the properties of the crystal and nonlinear optic crystal and the pumpe source have been discussed by using the theory about frequency-tripling, and how to set up a basic mode and thermal stable 447nm blue light laser by using the new design method which is expounded on this paper has been theoretically and experimentally studied. The research mainly includes the following several aspects:1. Phase matching characteristics for the second harmonic generation (SHG) and third harmonic generation (THG) in KTP and LBO crystals were simulated according to their physicochemical and optical properties. After comparision of calculation results, LBO with type-Ⅰcritical phase matching (CPM) and KTP with type-ⅡCPM were chosen for SHG and THG, respectively.2. Advantages and disadvantages of side-pumped and end-pumped were compared. The concrete conditions of the frequency tripling system and the comparison results show that LD-side-pumped laser is more suitable for the 447nm blue light laser system. The Nd:YAP crystal was chosen for the side-pumped system. The structure of the pump source, the water-cooling system and the polarization characteristic of the fundamental wave were discussed and analyzed.3. According to the theory of the laser resonant cavity, and basic on the ABCD matrix, the stability conditions of the resonant cavity, the conditions of basic mode generation and the thermal stability of the laser have been studied. Utilize the interrelationship of the factors to establish a design method about how to attain the basic mode and dynamic thermal stable laser.4. Basic on the V cavity structure and the actural conditions, the equipments (including laser crystal, nonlinear optical crystal and pump system) were chosen for the laser system. An experimental system was set up by using the design method which is expounded on this paper.5. A fundamental mode and thermal stable 447nm blue light laser was attained. Its highest out-put power is 83.5 mW. And the input-output efficiency, output spectrum, light spot and power stability were measured by the experiment. The experimental result shows that using the design method which is expounded on this paper can attain a fundamental mode and thermal stable laser.