Wavelength and temperature dispersion of refractive index of thin films

The m-lines guided mode technique is demonstrated as a powerful tool for the measurement of wavelength and temperature refractive index dispersion in thin films. The proper treatment of results reveals measurement uncertainties of the order of 10(-3) for the refractive index, and a sensitivity to changes in this quantity of the order 10(-6). Furthermore, the thickness of the films can be established to a precision of 1nm. Using an optical stack consisting of a silicon wafer substrate, a low index buffer layer (index 1.52), topped with a polymer blend guiding film, The wavelength dispersion of the change of refractive index of the guiding film with temperature has been successfully measured. The temperature dispersion of the refractive index of the guiding layer is of similar to -6.7x10(-5) /K.