This is the refractive index data for 150 nm Ag thin film measured using the Sopra GES 5E spectroscopic ellipsometer. The data is extracted using the bulk calculation model of the WinEliII software. The incidence angle was 75 degrees, the analyzer was kept at 45 degrees. The film was deposited using e-beam evaporation technique in Lab 600H. The substrate used was silicon wafer of 525 microns thick. 2 nm of titanium was deposited initially as an adhesion layer and 1 nm of AgOx was deposited as the seed layer. It was followed by deposition of Ag (50 nm each for 3 times). The deposition rate of all the metals was 4 angstorm/sec with a base pressure of 1.5*10^(-6) mbar.