Research And Application Of F-P Interferometer Based On Pbse Quantum Dot

Quantum confinement effects are shown when the quantum dot charge carrier size is comparable to that of the Exciton Bohr radius,which means that the quantum dots will have special properties such as size adjustable.In this thesis the thermal-optical effect of PbSe quantum dots using the Z-scan method is investigated.The PbSe QDs films were made and the thermal-optical coefficients in the magnitude of 10-4 K-1 are obtained.We came up with the idea of using its high thermal-optical coefficient to fabricate optical fiber sensors.Firstly,a PbSe/UV colloidal quantum dot with a doping content of 2 mg/ml was prepared and filled into a hollow fiber with an inner diameter of 125um.The Fabry-Perot(F-P)interferometer was then been fabricated by inserting silver-plated fibers and ordinary single-mode fibers at both ends of the hollow fiber.Finally,the F-P optical fiber sensor with quantum dots sequentially was tested using semiconductor laser light sources with wavelengths of 473nm,632nm,808nm and 980nm.By adjusting the light intensity the interference fringe peak wavelength ?k's moved.The variation of interference fringes in different temperatures is also studied in the experiment.Combined with the PbSe QDs absorption spectrum,the movement rule of interference fringes under different wavelength light sources was analyzed,meanwhile the movement rule of interference fringes under the condition of temperature change was also analyzed.The main innovation of this thesis is the application of PbSe colloidal quantum dots with high thermo-optic coefficient to sensing,making F-P interferometer with temperature and light-sensing ability.From the experimental results,it is found that the movement of the center peak ?k wavelength of interference fringes is linearly correlated with the change of light intensity,and the wavelength of the light source affects the linear slope.In addition,the temperature test experiment has shown the sensor having a higher sensitivity to temperature when compared to the ordinary F-P interferometer.Experimental data shows that PbSe colloidal quantum dots is indeed one of the excellent materials for the construction of optoelectronic devices.