Journal of the Optical Society of America B
Entangled-photon ellipsometry
Ayman F. Abouraddy, Kimani C. Toussaint, Alexander V. Sergienko, Bahaa E. A. Saleh, Malvin Carl Teich
Abstract
Performing reliable measurements in optical metrology, such as those needed in ellipsometry, requires a calibrated source and detector, or a well-characterized reference sample. We present a novel interferometric technique to perform reliable ellipsometric measurements. This technique relies on the use of a nonclassical optical source, namely, polarization-entangled twin photons generated by spontaneous parametric downconversion from a nonlinear crystal, in conjunction with a coincidence-detection scheme. Ellipsometric measurements acquired with this scheme are absolute, i.e., they require neither source nor detector calibration, nor do they require a reference.