| Rare-earth doped optical glasses have wide application prospects in laser, communication and lighting devices. Among them, the 4f 2 shell electronic configuration of praseodymium ion is relatively simple, and energy levels are abundant. So it has effective multiple channel radiative transition in the ultraviolet, visible and infrared region. These characteristics make praseodymium ions become an important activator in luminescent materials. At the same time, it is necessary for extending the work wavelength to C band to find suitable glass materials for obtaining the optical amplifier with high gain, wide bandwidth and compact type. In addition, optical waveguide devices have wide application prospect in the visible waveguide sources because of the super fluorescences have very strong direction performance.Based on this consideration, Pr3+-doped aluminum phosphate glasses have been designed and fabricated, and optical and spectral characteristics are explained. The followings are results this work achieved:1. Pr3+-doped LCBALP glasses with high near infrared emission which are suitable for optical fiber have been prepared. Based on absorption spectrum, Judd-Ofelt parameters ?2, ?4 and ?6 have been derived to be 9.17?10-20 cm2,16.50?10-20 cm2 and 2.41?10-20cm2, respectively. Under 488 nm wavelength excitation, ?1.47?m near infrared emission has been detected. The maximum stimulated emission cross-section, effective bandwidth, and spontaneous emission probability corresponding to the 1D2?1G4 transition are derived to be 12.28?10-21 cm2 and 158 nm and 719.4 s-1, respectively. The quantum efficiency of 1D2 level is 85.4%. Near infrared emission efficiency indicates that Pr3+-doped LCBALP optical glasses can realize the optical signal amplification to expand the E+S band effectively and have potential for the special band fiber amplifier. In the meantime, it can provide ideas for explorating new broadband optical amplification devices.2. Pr3+-doped NMAP-1 glass waveguides which can support infrared single-mode signal transmission have been fabricated by ion exchange technology. Based on absorption spectrum, Judd-Ofelt parameters ?2, ?4 and ?6 have been derived to be 6.38?10-20 cm2,20.30?10-20 cm2 and 0.40?10-20 cm2, respectively. Under 442 nm wavelength excitation, 1462 nm near infrared emission has been achieved. The maximum stimulated emission cross-section, FWHM, and spontaneous emission probability corresponding to the 1D2?1G4 transition are derived to be 1.14?10-20cm2,116 nm and 514.0 s-1, respectively. The results show that the emission intensity and spectral band width can meet the requirements of infrared waveguide amplifier. Therefore, they are the potential materials for waveguide devices. Pr3+-doped NMAP-1 planar glass waveguides can support visible multi-mode and infrared single-mode signal transmission. The biggest change of refractive index is 0.0083, which can be achieved in coupling infrared single-mode fiber efficiency. In summary, Pr3+-doped NMAP-1 glasses have a promising potential for the development of infrared waveguide devices.3. Pr3+-doped NMAP-2 glass waveguides which can support visible single-mode signal transmission have been fabricated by ion exchange technology. Based on absorption spectrum, Judd-Ofelt parameters ?2, ?4 and ?6 have been calculated to be 8.04?10-20 cm2,19.85?10-20 cm2 and 0.54?10-20 cm2, respectively. Under 443 nm wavelength excitation, 597.0nm visible emission has been monitored. The spontaneous emission probability and experimental lifetime, corresponding to the 1D2?3H4 transition are derived to be 824.3 s-1 and 144.1?s, respectively. The quantum efficiency of 1D2 level is 87.7%, showing that it is expected to achieve effective emission from 1D2 level. In summary, Pr3+-doped NMAP-2 glasses have a promising potential in the visible waveguide sources.The present research indicates that aluminum phosphate glasses with excellent thermal stability are an attractive material in fabricating special broadband fiber amplifier and waveguide devices matching visible, infrared single-mode fiber. Based on the excellent performance of Pr3+-doped aluminum phosphate glasses, we believe that they are expected to be used as potential and attractive candidates for developing functional devices such as infrared signal amplification and visible waveguide sources. |
PDF Full Text Request