Blue Laser Pumped Pr:YLF Red Dual-wavelength Lasers

The value of studies on trivalent praseodymium ion is being obvious with the urgent market demand of visible lasers. In recent years, the pump source of gain medium with praseodymium ion doped is developing rapidly, and the emission spectra can obtain an efficient overlap with the absorption peak of praseodymium ion. And new materials used as laser medium continue to emerge and develop. These factors contribute a lot to focus the researchers’eyes on the study of visible solid-state lasers. In particular, the important research value of the dual-wavelength lasers display in many fields, especially the nonlinear optical transition field. As a result, the study using blue light pumping Pr:YLF crystal to produce visible dual-wavelength lasers is of great significance.In this dissertation, using deflecting plasma sputtering deposition technical equipment to prepare the laser mirrors, and then we use a blue laser diode to pump Pr:YLF crystal to achieve640nm and698nm dual-wavelength lasers. The main contents can be divided into the following four parts.First of all, the introduction of solid-state lasers’background, research progress of praseodymium ion and Pr:YLF lasers, helps us to get a general comprehension. Secondly, using devices to attain the absorption spectra and emission spectra of a5mm long,0.5a.t.%doped Pr:YLF crystal. And performing a theoretical analysis of some parameters such as the spot radius, cavity loss, output-mirror’s transmission, crystal length and input power, have influence on the performance of Pr:YLF red dual-wavelength lasers such as properties of pumping rate, threshold, slope efficiency and output power, and so on.Thirdly, details of preparing laser mirrors experimentally by using sputtering technology are described combining with actual coating experiences. The depiction starts from experimental equipments to the design and optimization of optical films, and then to the analysis of optical influence of films’thickness and incident angle, finally ends with actual film-making sputtering procedures.Finally, a red640nm and698nm dual-wavelength lasers are achieved by using InGaN laser pumping Pr:YLF crystal. We accommodate the lasers to continuous-wave and quasi continuous-wave working condition by pump modulation. Through oscilloscope and photoelectric detector, we have observed the competition curve of640nm and698nm, and the fluctuated curve of output power. In the quasi continuous-wave working state, we changed the frequency of modulation signal to100Hz and1000Hz respectively and measured the output performance when the resonant cavity is relatively stable. The experimental results show that, gain competition curve of these two wavelengths can be switched between order and disorder state by tuning the cavity length and modulating the pump source. This dissertation ends with a comparative analysis of the output spectra between the dual-wavelength lasers and single-wavelength lasers.