Accurate determination of the optical performances of antireflective coatings by low coherence reflectometry

We propose to use optical low coherence reflectometry to measure the reflectance of both faces of a plane substrate with one side coated in antireflective layers. We identify, through a detailed theoretical analysis, the optimum configuration and evaluate the expected sensitivity and accuracy of some realistic examples. Finally, we experimentally demonstrate the ability of this method to quantify reflection coefficients as low as 5x10(-7). That way, an accurate characterization of the performances, at 1550 nm, of antireflective coatings deposited on various plane substrates is achieved.