Characteristic Of Diode-pumped Yb³⁺-doped Y₂SiO₅ Laser

As ultra-short lasers were widely applicated in industrial, medical, communication and so on, ultra-short laser technology are developed rapidly. LD pumped solid-state lasers have become the central focus of recent researches, due to their simple structure, high efficiency, stable property. Yb-doped crystals are the important part of ultrafast laser. Yb³⁺-doped Y2SiO5 is oxyorthosilicate biaxial monoclinic crystal with high thermal conductivity and wide emission crosssection. It is an ideal laser crystal in the realization of LD pumped ultralfast lasers. This dissertation mainly researched the laser characteristics LD pumped YbYSO crystal. Main contents can be summarized as follows:1. In this part we introduced the development history of ultrafast lasers, as well as the characteristics of Yb³⁺-doped crystal.2. In this part we introduced the main theory, such as tunable laser theory, the mechanism of mode-locking including passive mode-locking with SESAM and self-mode locking, the principle of de-dispersion.3. We have summarized the spectrum charateristics and thermal conductivity of Yb:YSO crystal. And we calculated the temperature distribution inside the Yb:YSO crystal, the distortion of the end-pumped face, and the thermal lens focal length by solving the Poisson equation using the finite difference method. We also measured the thermal lens focal length using a plane-plane cavity. The experimental results were consisted with the calculated results. By inserting a SF10 prism into the cavity as a tuning element, widely tuned laser from 1029nm to 1081nm was achieved.4. We sutdy the performance of passively mode-locked Yb:YSO laser with a SESAM. The maximum output power of 1.6 W was achieved with pulse width of 1.6ps. The center wavelength was 1043.5nm and the bandwidth was 1nm. In addition, we also achieved Yb:YSO self-mode-locked laser operation with pulse width of 1.2ps, and the maximum output power was 1.05W at the center wavelength of 1061nm. The bandwidth was 1.8nm.5. Novel single walled carbon nanotuble saturable absorber (SWCNT-SA) was successfully fabricated and was used in generating passively mode-locked Yb:YSO and Yb:SSO. The maximum output power of Yb:YSO/SWCNT-SA laser was 1.1W, and the pulse width was 1.2ps at the center wavelength of 1058nm.6. Passively mode-locked Yb:SSO laser with a SWCNT-SA was also achieved. The maximum output power was 940mW, and the pulse width was 5.4ps at the center wavelength of 1063nm. The bandwidth was 1.6nm. In order to achieve femtosecond operation, a pair of SF10 uncoated prisms was inserted into the cavity and the pulse width was 880fs. The maximum output power was 720mW with the center wavelength of 1061nm, and the bandwidth was 1.9nm.