Optical Propagation Of Near-infrared Broadband PbSe-quantum-dot Doped Fiber Based On Sodium-aluminum-borosilicate Silicate Glass

Quantum dots(QDs)are a kind of semiconductor nanocrystals.In recent years,QDs attract much attention due to the quantum-size effect,surface effect,and tunable absorption-emission wavelengths.In IV-VI QDs,PbSe QD is remarkable due to the high quantum yield,low excitation threshold and high luminous efficiency.In this dissertation,we report the fabrication of sodium-aluminium borosilicate glass and QDs doped fiber using a high temperature two-step annealing method.The absorption and emission spectra of QD doped glass and QD doped fiber are analyzed and compared.QDs within the fiber have size of 4.73?0.25 nm.Changes in absorption,photoluminescence profiles and pump power at 980 nm are measured experimentally,the absorption peak at 1450 nm and the emission peak at 1500 nm.Decay of pump power within the fiber,variation of photoluminescence and peak wavelength in respect to fiber length are further measured.We determine the attenuationcoefficient varying with wavelength,pumping excitation threshold and saturation power in the fabricated fiber,and explained our observation using level-transition theories and surface effects of QDs.In this dissertation,our experimental study on PbSe QD doped fiber have a significance to the development of the near-infrared QD doped fiber-gain devices in the further.