Structure-Terahertz Property Relationship and Ultrafast Laser Modification in Borosilicate, Tellurite, and Chalcogenide Glasses
Date
2022-12
Authors
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Publisher
New York State College of Ceramics at Alfred University. Inamori School of Engineering.
Abstract
This thesis is focused on developing structure-terahertz (THz) property relationships for three distinct glass families, i.e., oxide borosilicate, oxide tellurite, and non-oxide chalcogenide glass families. A comprehensive structural study has been carried out using spectroscopy techniques, e.g., nuclear magnetic resonance (NMR), infrared (IR), and Raman spectroscopy. THz time-domain spectroscopy (THz-TDS) is used to record refractive indices at THz frequencies.
Unique structure-THz property relationships are observed for borosilicate, tellurite, and chalcogenide glass families. Sodium borosilicate glasses with a depolymerized glass network composed of [BO4]−, Q4, and Q3- structural units and danburite and reedmergnerite borosilicate ring units with mixed bonding and an interconnected network measure higher THz refractive indices than polymerized networks. Sodium tungsten tellurite and lanthanum tungsten tellurite glasses have higher THz refractive indices correlated to a glass network with substantial TeO2 and WO3 content with mixed Te-O-W linkages and TeO2- or WO3-rich content with homonuclear Te-O-Te or W-O-W linkages, respectively. Unary, binary, and ternary chalcogenide glass systems record a range of THz refractive indices ultimately controlled by <r> and, therefore, elemental composition, structural units, and network. Arsenic sulfide, arsenic selenide, germanium selenide, and germanium arsenic selenide glass systems record the maximum THz refractive index at <r> = 2.4 for As40S60 and As40Se60, <r> = 2.8 for Ge40Se60, and r<r> = 2.5 for Ge10As30Se60, respectively.
High-repetition rate femtosecond laser irradiation of sodium borosilicate glasses supports depolymerized glass networks with no change in NMR signal but larger change in the THz refractive indices. Low-repetition rate femtosecond laser irradiation of arsenic sulfide and arsenic selenide chalcogenide glasses measure minimal structural changes and varying degrees of THz refractive indices changes. Linear visible-THz refractive indices correlation in the sodium borosilicate glass system shows higher measurable refractive indices for depolymerized borosilicate networks and LWIR-THz refractive indices correlation in the chalcogenide family shows linear, nonlinear, and anomalous behaviors.
Our results reveal the ability to customize the glass family, system, and composition to design a glass with targeted THz optical properties and the use of ultrafast laser irradiation to modify glass structure and THz properties.
Description
Thesis completed in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Materials Science and Engineering at the Inamori School of Engineering, New York State College of Ceramics at Alfred University
Type
Thesis
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Keywords
Optical glass