Measurement of the refractive index of electrically poled soda-lime glass layers using leaky modes

Abstract

Oven, Robert (2016) Measurement of the refractive index of electrically poled soda-lime glass layers using leaky modes. Applied Optics, 55 (32 Electrically poled layers have been formed in soda-lime glass using graphite electrodes in air. The refractive index and thickness of the poled glass layers have been measured by the analysis of leaky optical modes. These modes are supported by the poled layer and can be determined by analysis of the optical reflectivity measured with a prism coupler arrangement. A relatively constant refractive index ~ 1.486 in the poled glass region is measured, which is ~0.03 below the substrate index. The reflectivity data shows that the transition between poled and un-poled glass is very sharp and is consistent with ion transport models. The thickness of the poled glass region is consistent with the removal of Na + and K + ions from the poled region. The index and depth data is confirmed by interferometric measurements. The tensile stress in the poled glass layer is also estimated from optical birefringence measurements and is estimated to be ~0.3 GN/m 2 .

Ellipsometry-based study of glass refractive index depth profiles obtained by applying different poling conditions

“…There, the peak is approximately 0.002 higher than the refractive index of the untreated sample. In the other work of the same author [22] the peak in soda-lime glass of the similar composition as here, poled with 261 o C, 400 V, 5h, was not observed. However, the peak reported here is significantly exceeding the refractive index of an untreated microscope slide.…”

“…For this purpose, poled glass n(d) should be determined first. The poled glass n(d) were obtained from interferometry [3], by the use of leaky modes [22] and micro-IR reflectometry [3], for example. These studies agree that the refractive index of depleted region is approaching to the one of fused silica and towards bulk is is approaching to that of untreated glass.…”

AC impedance of poled glass during de-poling

“…From the charge transported during the whole of the poling and depoling process (=1.03 C) and the composition and density of the above glass a poled layer depth d =2.3µm was estimated. This was verified by optical measurements using the analysis of leaky modes, which gave d=2.26µm [11]. The total time for the de-poling stage was 38 min.…”

“…These electrodes are thought to be at least partially of the non-blocking type allowing some hydrogen injection from the air. They also result in a poled glass that has a good surface finish to allow for optical assessment [11]. Figure 1 shows the electrical arrangements used for the experiment.…”

Определение Толщины Поляризованной Области Стекла

“…Многокомпонентные силикатные стекла, содержащие как способные к перемещению ионы-модификаторы [1], так и неподвижный сеткообразователь (кремний), позволяют модифицировать их приповерхностную область посредством термической поляризации. При поляризации таких стекол за счет ухода под действием электрического поля щелочных ионов в глубь стекла изменяются состав [2] и структура [3] поляризованной прианодной области, ее показатель преломления [4], объем [5], также у стекла появляется способность генерировать вторую оптическую гармонику за счет снятия электрическим полем центральной симметрии материала [6]. Эти изменения представляют интерес для создания элементов и структур для фотоники [7,8].…”