Excimer-laser-induced emission bands in fused quartz

Structural change of OH-free fused quartz tube by blowing with hydrogen–oxygen flame

“…In the previous investigations, we studied the characteristics of the UV absorption bands in FQ [5,6]. FQ has an absorption band near 5 eV called the B 2 band.…”

“…A number of models for the origin of the B 2 b band has been proposed: [4] ODC(II), twofold-oxygen-coordinated silicon [TOCS(@Si:)], and Ge-related oxygen vacancies such as BGeÁ Á ÁSiB. We assumed, in previous papers [5,6], that the origin of B 2 b is TOCS. During the blowing process, H 2 O and H 2 molecules must react with ODC or TOCS as Utilizing these reactions, B 2 bands near the OSS must be bleached.…”

“…In addition to such semi-macroscopic defects, FQ has absorption bands due to point defects in the ultraviolet (UV) region of K 300 nm [1]. A well-known absorption band in FQ exists at %5 eV, called the B 2 band [3][4][5]. At least two kinds of B 2 bands are known [3,4].…”

Ultrasonic microspectroscopy characterization of silica glass

“…8,11 This difference was closely associated with the granular structure in fused quartz and consequently inhomogeneous OH distribution localized at the grain boundaries, although synthetic silica glass is rather homogeneous in its OH distribution because of the production method. 5,10 Samples N and NP have the same level in OH content, containing 160-180 ppm larger content than sample HRP, so that they have lesser viscosities due to the softening of the structure. So, we can relate the viscous effect of the OH content to the acoustic decreases of the longitudinal properties of V l , c 11 , and , as described in Sec.…”

“…3 Further, the OH ion content is one of the most important parameters for evaluating the quality and characteristics of silica glass because OH ions are related to various physical and optical properties of silica glass, such as viscosity at high temperatures, 7,8 Rayleigh scattering loss, 9 and excimer laser resistivity. 10,11 Its properties are also considered to vary greatly with thermal history. Thus, development of proper methods and systems for precisely characterizing the silica glass and evaluating the fabrication processes are needed in order to assure acceptable products.…”