The objective of this PhD study is to fabricate and characterize new magneto-optical glasses in terms of thermal stability, mechanical property and Verdet constant for magneto-optical waveguide and sensing applications. Firstly, 3 heavy metal oxides magneto-optical (MO) glasses were fabricated and characterized including magneto optical ion exchangeable glasses, magneto optical photosensitive glasses. Thanks to the high polarizability of Te4+ ions and the high transparency from visible wavelengths up to the mid-IR, TeO2-based glasses exhibit the required characteristics for the development of efficient magneto-optic fiber components, such as high refractive index, optical and magneto optical properties at infrared wavelengths etc. Besides the TeO2, diamagnetic heavy metal oxide glasses, such as Bi2O3 and PbO, due to their mass and high polarizability of ions Pb2+ and Bi3+, are appealing for magneto optical sensors because of their temperature-independent Faraday Effect, small phonon energy, large refractive index and low-melting properties. In this PhD study, TPB(TeO2-PbO-B2O3) glass, PBB (PbO-Bi2O3-B2O3)glass have been studied and based on these four systems, ion exchangeable glasses and fs-laser-photosensitive glasses, were designed, fabricated and characterized. The study on improving Verdet constant was carried out. Verdet constant of 0.135 min/G.cm was obtained on glass with the composition of 30PbO-60Bi2O3-10B2O3 for PBB system. For TPB system, the highest Verdet constant was 0.2min/G.cm for glass with composition of 58.8TeO2-39.2PbO-2B2O3. Secondly, based on the magneto optical glasses with good Faraday rotation performance, the investigation of different techniques, such as ion exchange technique and fs laser writing, for magneto optical waveguides or sensing devices fabrication were carried out. The study on ion exchange on magneto optical glasses was performed, considering the influences from different salt concentration, temperature and time etc. Three ion exchangeable MO glass systems were designed and fabricated. Different characterization methods such as DTA, UV-VIS, FTIR, Raman, Magneto optical test, XRD, XPS, FESEM and EDX, were employed to investigate the influence of ion exchange to the property of MO glass. Optimized ion exchange conditions were obtained. Under the optimized conditions, glass after ion exchange get refractive index change varies 0.01, and the Verdet constant after ion exchange was enhanced. The study on fs laser writing MO waveguides on magneto optical glasses was performed, including the laser writing conditions setup, and glass samples preparation and characterization, also the waveguide fabrication study was evolved. MO glass for fs laser writing were designed and fabricated. Different characterization methods were employed for the aim of investigating optimized conditions for fs laser writing. Different fs laser parameters such as power, speed, angle and repetitions were studied. And the waveguide quality were characterized using FESEM, sureface profilometer etc. The refractive index and Verdet constant of obtained waveguides were measured, and their values depended on the power used. The light propagation of obtained waveguides was tested using a home-made optical bench. The waveguides exhibited good light propagation performance. Thirdly, the attempt on MO sensing devices was preliminary studied based on the MO glass. One magneto optical waveguide prototype based on ion exchangeable sodalime glass plus sputtered MO layer was fabricated and evaluated. One magneto optical waveguide prototype based on fs laser writing on MO glasses was also fabricated and evaluated. A home-made single-light-way DC magnetic optical setup was constructed in POLITO for measurement of Verdet constant, and an optical apparatus for waveguide coupling and measurement was constructed in Henan university of Technology of China for the evaluation of magneto optical signal through MO waveguides.

Fabrication and Characterization of new Magneto Optical Glass for magneto optical waveguide and sensing applications / Wang, Hui. - (2016). [10.6092/polito/porto/2659042]

Fabrication and Characterization of new Magneto Optical Glass for magneto optical waveguide and sensing applications

WANG, HUI
2016

Abstract

The objective of this PhD study is to fabricate and characterize new magneto-optical glasses in terms of thermal stability, mechanical property and Verdet constant for magneto-optical waveguide and sensing applications. Firstly, 3 heavy metal oxides magneto-optical (MO) glasses were fabricated and characterized including magneto optical ion exchangeable glasses, magneto optical photosensitive glasses. Thanks to the high polarizability of Te4+ ions and the high transparency from visible wavelengths up to the mid-IR, TeO2-based glasses exhibit the required characteristics for the development of efficient magneto-optic fiber components, such as high refractive index, optical and magneto optical properties at infrared wavelengths etc. Besides the TeO2, diamagnetic heavy metal oxide glasses, such as Bi2O3 and PbO, due to their mass and high polarizability of ions Pb2+ and Bi3+, are appealing for magneto optical sensors because of their temperature-independent Faraday Effect, small phonon energy, large refractive index and low-melting properties. In this PhD study, TPB(TeO2-PbO-B2O3) glass, PBB (PbO-Bi2O3-B2O3)glass have been studied and based on these four systems, ion exchangeable glasses and fs-laser-photosensitive glasses, were designed, fabricated and characterized. The study on improving Verdet constant was carried out. Verdet constant of 0.135 min/G.cm was obtained on glass with the composition of 30PbO-60Bi2O3-10B2O3 for PBB system. For TPB system, the highest Verdet constant was 0.2min/G.cm for glass with composition of 58.8TeO2-39.2PbO-2B2O3. Secondly, based on the magneto optical glasses with good Faraday rotation performance, the investigation of different techniques, such as ion exchange technique and fs laser writing, for magneto optical waveguides or sensing devices fabrication were carried out. The study on ion exchange on magneto optical glasses was performed, considering the influences from different salt concentration, temperature and time etc. Three ion exchangeable MO glass systems were designed and fabricated. Different characterization methods such as DTA, UV-VIS, FTIR, Raman, Magneto optical test, XRD, XPS, FESEM and EDX, were employed to investigate the influence of ion exchange to the property of MO glass. Optimized ion exchange conditions were obtained. Under the optimized conditions, glass after ion exchange get refractive index change varies 0.01, and the Verdet constant after ion exchange was enhanced. The study on fs laser writing MO waveguides on magneto optical glasses was performed, including the laser writing conditions setup, and glass samples preparation and characterization, also the waveguide fabrication study was evolved. MO glass for fs laser writing were designed and fabricated. Different characterization methods were employed for the aim of investigating optimized conditions for fs laser writing. Different fs laser parameters such as power, speed, angle and repetitions were studied. And the waveguide quality were characterized using FESEM, sureface profilometer etc. The refractive index and Verdet constant of obtained waveguides were measured, and their values depended on the power used. The light propagation of obtained waveguides was tested using a home-made optical bench. The waveguides exhibited good light propagation performance. Thirdly, the attempt on MO sensing devices was preliminary studied based on the MO glass. One magneto optical waveguide prototype based on ion exchangeable sodalime glass plus sputtered MO layer was fabricated and evaluated. One magneto optical waveguide prototype based on fs laser writing on MO glasses was also fabricated and evaluated. A home-made single-light-way DC magnetic optical setup was constructed in POLITO for measurement of Verdet constant, and an optical apparatus for waveguide coupling and measurement was constructed in Henan university of Technology of China for the evaluation of magneto optical signal through MO waveguides.
2016
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2659042
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