S4) A thin film system consists of light oil at the top ( n=1.4 ); glass as the film ( n=1.8 ); heavy oil at the bottom ( n=1.6). Light, that has a wavelength of 320nm in vacuum, travels through tip material and is incident upon a thin transparent film. What thickness of film will cause third order bright reflection of this light? 800nm 444nm 222nm 400nm S4) A thin film system consists of light oil at the top ( n=1.4 ); glass as the film ( n=1.8 ); heavy oil at the bottom ( n=1.6). Light, that has a wavelength of 320nm in vacuum, travels through tip material and is incident upon a thin transparent film. What thickness of film will cause third order bright reflection of this light? 800nm 444nm 222nm 400nm