The refractive index and thickness of thin transparency measuredby Michelson interferometer

A new method is proposed to measure the refractive index and thickness of thin transparency simultaneously by Michelson interferometer.By the method,the optical path difference can be measured quantitatively by the changes in the numbers of the rings of equal inclination,when the angles between lightpath and the measured objects inserted in Michelson interferometer vary.A relationship among the numbers of the rings,the angles between light and the measured objects,the thickness and the refractive index is deduced,then the thickness and refractive index of thin transparency can be calculated.The optical system is not necesary to change when it is calibrated well before the measurement and the systematic errors can be reduced further.