Broadband Infrared Luminescent Materials Doped With Transition Metal Ions

Photonic glass and fiber play a crucial role in the information technology,because of its advantages such as excellent optical properties,easy fabrication,high resistance to laser and thermal damage threshold,high mechanical and chemical stability.The speedy development of broadband telecommunication technology hinges on fundamental improvement in fiber infrastructure.Especially,broadband fiber amplifier plays an irreplaceable role in modern telecommunication system because it can support in situ and broadband optical signal amplification.A large bandwidth of fiber amplifier is urgently required to produce more channels,which is primarily resulted from explosive growth of the global internet traffic.In this work,we study the broadband emission properties of transition metal doped glass-ceramics and glass composite.The crystal field strength and the crystalline phases in glass-ceramics could be controlled by the heat treatment process,resulting in the controllable regulation of luminescence peak and bandwidth of transition metal ion-doped glass.Detailed research process and results in my work are as follows:?1?In Ni²⁺ions doped silicate glass-ceramics system,the emission spratra of a series of samples heat-treated at various temperature spots clearly shows the relevancy between emission peaks,temperature and sample colors,realizing the controllable adjustment of the center of broadband emission.The structure and optical characterizations demonstrate that the phenomenon is originated from the distortion of lattice and the ligand field changes of activated ions which doped in glass-ceramics.In addition,it can be observed that the Ni²⁺-doped glass fiber exhibit different luminescent properties and colors with the increase of heat-treated temperature.The effects of Ni²⁺doping concentrations and glass components on the broadband luminescence are also investigated.?2?Ni²⁺-doped fluorosilicate glass-ceramics with broadband emission are prepared.The structural characterizations show that Rb₂Si F₆ nanocrystals precipitated from the glassy phase glass-ceramics embedded with Cs₂Si F₆ nanocrystals can be fabricated in the sample with the composition of 20CsF-20Zn F₂-60Si O₂:Ni²⁺.By rational control of the heat-treatment temperature,the broadband NIR emission covering the 1200-2000 nm wavebands can observed by using 808 nm laser as excitation source at room temperature.The origin of the broadband emission has been discussed and it should be attributed to the typical ³T_2g?³F??Cs₂Si F₆ lattice.?3?We present the design,fabrication and experimental implementation of a novel fluorosilicate photonic glass-ceramics?20KF-20Cd F₂-60Si O₂?with broadband luminescence.We demonstrate that precipitated nanocrystals can be tuned by changing the heat treatment temperature.This proposal offers an excellent opportunity for controlling the local environment around Ni²⁺dopant.Consequently,the broadband and flat emission covering a waveband from 1200 nm to 2400 nm with a bandwidth of?605 nm can be realized.The possible physical mechanism,which can be attributed to the gradual change of nanocrystals from K₂Si F₆ to KCd F₃ with the enhancement of the heat treatment temperature,is also discussed.?4?Borophosphate glass composite?CZPB?containing Cr²⁺:Zn S crystalline powders has been fabricated.It exhibits Mid-IR luminescence in the waveband region from 1700 to 2900nm with the full width at half maximum?FWHM?of about 690 nm.In addition,the materials also can be fabricated into fiber without obvious change of the characteristic luminescence band.The results provide new opportunities for the construction of the broadband fiber light source operating at Mid-IR waveband region.?5?A series of gradient optically active glass-ceramics and fibers which exhibit gradient local field environment of active centers and the resultant optical response have been described.We show that regular and vivid change of sample colors,emission peaks,ratio intensity can be obtained via rational control of the heat-treated temperature.Furthermore,elaborate variation can be realized in the micro region by providing electric field and laser irradiation.The structure and optical characterizations demonstrate that the phenomenon is originated from the distortion of lattice and the ligand field changes of activated ions which doped in glass ceramics and fibers.It could be potentially advance the sensor technology and applied in spectrum modulation,decoration and multicolored laser-micro-engraving.