The thermal expansion behavior of Graphite/Epoxy Laminates between 116 and 366 degrees Kelvin was investigated using a novel implementation of the Priest interferometer concept. This thesis describes the design, construction and use of the interferometer along with the experimental results it was used to generate. The experimental program consisted of 25 tests on 25.4 mm and 6.35 mm wide, 8-ply quasi-isotropic T300/5208 graphite/epoxy specimens and 3 tests on a 25.4 mm wide unidirectional specimen. Experimental results are presented for all tests along with a discussion of the interferometer's limitations and some possible improvements in its design. / Master of Science