Superfluorescent Fiber Sources And Solid-State Laser Device

Laser is one of the most important invention in last century, which given a deep revolution in human society and advance science and technology greatly.Superfluorescent fiber sources (SFS's), also be called broad-band sources, were rare-earth -doped fibers under laser pumping produced a state of transition between fluorescent and laser. Which was the amplification of the spontaneous emission (ASE). Compared with super-luminescent diode (SLD), SFS's have advantage of high temperature stability, broad half-width of the spectral line, high output power, dependability, compact and can easily couple into single-mode fiber, most of all. By doping different rare-earth ions, the SFS's can be operation in different wavelength regions. In this paper, the experimental results on indigenous Yb-doped double-cladding fiber superfluorescent source pumping by 975 nm LD were reported. The basic characteristics, such as the output power-absorbed pumping-power, output band-width-absorbed pumping-power, have been studied. The output power 3.4mW while the slope efficiency about 1%; central wavelength of superfluorescent is 1076 nm, with a 50 nm 3dB bandwidth. If improving the pumping light quality and collimating-tbcusing, the output power and slope efficiency would be increasing.Longitudinal-pumping solid-state laser have advantage of high efficiency, good beam quality due to good spatial match between the pumping beam and the laser cavity mode, compact and dependability. End-pumping became one of the most common pumping construction. The optimum of end-pumping solid-state laser was one of the most interest areas for solid-state laser design. In this paper, using the circulating photon flux approach, given the laser medium'optimum length and output mirror optimum reflectivity expressions. They were related not only to the laser crystal parameters, but also to the resonator parameters or pumping condition. The result were compared with the experiments of Nd:YAG laser, there were a good consistent.Pulse solid-state laser was complicated than CW solid-state laser. Theories of the pulse solid-state laser were introduced. Based on the general expression of output power (energy), output mirror optimum reflectivity was given.Tunable ultraviolet laser is of important for practical application in many science researches. The majority of known tunable UV sources were complicated devicescomprising some tunable laser in visible region and subsequent nonlinear frequency conversion. In recent years, based on 5d-4f transitions of Ce3+-doped laser mediums, such as Ce:LiCaAlF6 (Ce:LiCAF), Ce:LiSrAlF6 (Ce:LiSAF), Ce:LuLiF4 (Ce: LLF), can direct produce tunable ultraviolet laser output with UV pumping, and which also be an all-solid-state laser. They open up a new field for ultrafast optics research. In this paper, the ways of get tunable ultraviolet output and the Ce-doped ultraviolet laser crystals were introduced.