Group delay measurements of optical components near 800 nm

Phase-locked interferometry was used to measure the group delay of several optical components in the spectral region 700-850 nm. The dispersive and absorptive properties of several different types of linear filters were measured. Measurements of the absorption and dispersion of several linear, causal optical filters show that a generalized Kramers-Kronig relation does not exist for many commonly used filters. This result emphasizes the importance of making direct measurements of the dispersive properties of filters, since the dispersion of a linear filter cannot always be determined from a measurement of its absorption. Data are presented for a birefringent filter, dielectric mirror, Gires-Tournois interferometer, and titanium-doped sapphire. >