Título
SINGLE EXPOSURE REFLECTANCE MEASUREMENTS BY MEANS OF MULTIPLE ANGLES-OF-INCIDENCE WITH CONVENTIONAL AND UNCONVENTIONAL POLARIZATION STATES OF LIGHT
Autor
Victor Rico
Colaborador
RAFAEL ESPINOSA LUNA (Asesor de tesis)
Nivel de Acceso
Acceso Abierto
Materias
Resumen o descripción
"Here we present an option to measure the refractive index of materials by using the ellipsometry technique. In the traditional method a beam of polarized light is sent, at different angles, to the materials surface where it is reflected. The state of polarization of this reflected beam is analyzed (recorded) every time a new angle is given. With these values the Fresnel reflectance graphs are obtained and the refractive index is calculated.
Now we propose a method that is based on a high numerical aperture objective lens. A single recording is done. The process involves the study of the change of polarization state, associated to an incident illumination field, when it is reflected from the plane surface of the material. To perform this study the spatial distribution of light, at the pupil of the objective lens, is transferred by means of a lens to a CMOS 1280×1024 matrix detector. The image obtained as a result, contains the reflectance information at multiple and continuous local planes of incidence with a completed round. Then the distribution of light is studied with some computer programs, allowing the measurement of the Brewster angle and the deduction of the value of the refractive index asociated to the area under study.
In this work, the question about what kind of polarized light is the more appropriate illumination source that should be employed to obtain a measurement of the refractive index, using the technique shown here, is aswered. To give a response, BK7, MgF2, FS and SF12 glasses were excited with conventional and unconventional polarization fields, and the experimental results were compared with synthetic images computed through the Fresnel theory. Results show the use of unconventional polarization provides the most complete information and allows the spatial identification of anisotropies within spot diameters around 721 nm."
Fecha de publicación
julio de 2016
Tipo de publicación
Tesis de maestría
Recurso de información
Formato
application/pdf
Idioma
Inglés
Cobertura
León, Guanajuato
Audiencia
Público en general
Sugerencia de citación
Rico Botero, (2016). "Single exposure reflectance measurements by means of multiple angles-of-incidence with conventional and unconventional polarization states of light". Tesis de Maestría en Ciencias (Óptica). Centro de Investigaciones en Óptica, A.C. León, Guanajuato. 76 pp.
Repositorio Orígen
REPOSITORIO INSTITUCIONAL DEL CIO
Descargas
934