Determination of refractive index of ultraviolet light-cured optical adhesive by optical phase measurement method

Ultraviolet light curing is used frequently in the fields of optics and photonics. It is important to know the optical features of the materials that are used in these fields, according to the usage field more sensitive measurement methods are required. Knowing the refractive indices of ultraviolet light cured optical adhesive materials, which are particularly useful for assembling optical components, is an essential parameter for accurate device design and manufacturing. Aim of this thesis is to determine the refractive index of a urethane-acrylate optical adhesive material cured with ultraviolet light using optical phase measurement method. To reach that aim, firstly the urethane-acrylate adhesive material has been cured with a LED light source with a wavelength interval of 365-405 nm. To determine the thickness of the sample, which is prepared in a thin film form, examination has been carried out with SEM (scanning electron microscope). Samples, with their thickness measured in this way, are imaged with single wavelength diffraction phase microscopy (SWDPM) and their surface phase profile has been obtained with Fourier transformation technique and from this profile the refractive index has been calculated. In literature, SWDPM setup has never been used in order to measure the refractive index of transparent materials produced in a thin film form or cured with ultraviolet light. In that aspect this thesis subject provides original contribution to the literature as a method.