| Zeolites are crystalline porous materials with identical channel system, which have been widely used as separation, catalysts, ion-exchange materials. Especially, zeolites are used as host materials for the assembling of advanced host guest materials. Normally, research on zeolite synthesis is mainly focused on routes for the preparation of either large crystals or nanocrystals. Particularly, large zeolite single crystals are essential in the structure analysis, the study of crystal growth mechanism, adsorption and diffusion of guest molecules, and applications in advanced functional materials. Recently, single-walled carbon nanotubes(SWCNTs) are widely used as saturable absorber(SA) for the generation of pulsed fiber laser. However, SWCNTs-based SA for both mode-locked and Q-switched lasers has focused on low-power operation for their low thermal damage. Moreover, the previous SWCNTs-based SA fiber lasers can only fulfill one certain laser operation state: mode-locking or Q-switching, which highly limits its application. In this thesis, many synthesis parameters have been investigated in detail for the synthesis of large single crystals. Well-aligned single-walled carbon nanotubes have been synthesized by using AEL and AFI zeolite as template. These well-aligned SWCNTs own anisotropic optical absorption, which can act as excellent polarization sensitive saturable absorber for the pulse generation and laser operation states manipulation. The main contents are as follows:1) Effects of gel composition and crystallization conditions on the hydrothermal synthesis of ZAPSO-43(GIS) were investigated in detail. Perfect large optical clearly single crystals of GIS(around 250 ?m) were synthesized by optimizing the following synthesis conditions: crystallization temperature and duration, molar ratio of SiO2/Al2O3 and ZnO/Al2O3, content of HF acid and organic template dipropylamine(DPA). Single-crystal X-ray diffraction measurement shows that the as-synthesized GIS are of Fddd symmetry with lattice constants a = 9.9985 ?, b = 14.2565 ? and c = 14.5726 ?, ? = ? = ? = 90° and their unit volume is V = 2077.22 ?3.2) Large single crystals of AlPO-LTA with a size of 170 ?m have been synthesized by using n-Propylamine as the only structure directing agent. The effects of synthesis parameters on morphology and size of AlPO-LTA, such as aging duration, molar ratio of H2O/Al2O3, content of NPA and HF acid were investigated in detail. By using high content of water and NPA, large perfect cubic-shaped AlPO–LTA single crystals(170 ?m) are obtained in a HF free system. Single-crystal X-ray diffraction measurement shows that the as-synthesized AlPO-LTA crystals are of Pm3 m symmetry with lattice constants a = b = c = 12.02 ?, ? = ? = ? = 90° and their unit volume is V = 1736.65 ?3.3) We report the hydrothermal synthesis of SAPO-47(CHA) crystals by using n-Propylamine(NPA) as template. The resulting product sensitively depends on the gel compositions and synthesis procedure. By optimal the molar ration of SiO2/Al2O3, content of HF and NPA, large perfect cubic-shaped CHA crystals are obtained(size 260 ?m × 260 ?m), at a synthesis temperature of 200 °C with a crystallization of 50 h.4) We report the hydrothermal synthesis of SAPO-46(AFS) crystals by using n-Propylamine(NPA) as template. By optimal the molar ration of SiO2/Al2O3, content of HF and NPA, large perfect AFS crystals are obtained(size 180 ?m × 180 ?m). Single-crystal X-ray diffraction measurement shows that the as-synthesized AFS are of P63 cm symmetry with lattice constants a = b = 13.295 ?,c = 26.742 ?,? = ? = 90°,? = 120°, and their unit volume is V = 4093.56 ?3.5) Large single crystals of AEL and AFI have been synthesized by using hydrothermal methold. Then, well-aligned single-walled carbon nanotubes were fabricated by using AEL and AFI as template, which features anisotropic optical absorbption.6) Well-aligned single-walled carbon nanotubes(SWCNTs) were used as polarization saturable absorber for the generation of switchable pulsed lasers. By using such polarization sensitive SA, we achieve both mode-locking and Q-switching pulsed lasers by simply adjusting a polarization controller under a fixed pump power. Specifically, switchable pulsed erbium-doped fiber laser(EDFL) and ytterbium-doped fiber laser(YDFL) were obtained by using well-aligned SWCNTs that hosted in the nanochannels of AEL zeolite crystal as SA. The pump power was fixed at 310 mW in the EDLF, the operating central wavelength of mode-locking is about 1563.5 nm. The repetition rate and period are 21.68 MHz and 46.13 ns, respectively. The pulse width is about 180 fs. By adjusting polarization state, the mode-locked operation can be switched to Q-switched under the same pump power. The operating wavelength of the Q-switched EDFL is about 1563.4 nm, the temporal width and repetition rate of the Q-switched pulses are 4.3 ?s and 32.55 kHz, respectively. As for the YDFL, the pump power was fixed at 350 mW. The operating central wavelength is about 1048.3 nm. The repetition rate and pulse width are about 25.34 MHz and 463 ps, respectively. Moreover, the mode-locked operation can be switched to Q-switched under the same pump power by adjusting polarization state. The temporal width and repetition rate of the Q-switched pulses are observed to be 5.8 ?s and 27.85 kHz, respectively. The operating wavelength of the Q-switched YDFL is about 1039.5 nm. The well-aligned 0.4 nm SWCNTs that hosted in the nanochannels of AFI were used as polarization sensitive SA for the generation of switchable EDFL. The pump power was fixed at 330 mW, the operating wavelength of the mode-locked EDFL was about 1563.9 nm. The repetition rate and pulse width are about 23.2 MHz and 560 fs, respectively. By adjusting the polarization states, the mode-locked can be switched to Q-switched under the same pump power. The operating wavelength of the Q-switched EDFL is about 1568.5 nm, the temporal width and repetition rate of the Q-switched pulses are 5.2 ?s and 24.25 kHz, respectively. |
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