title: Comment on "Generalized grating equation for virtually imaged phased-array spectral dispersers".
abstract: I correct an error made by Vega et al. [Appl. Opt. 42, 4152 (2003)], who derived the spectral dispersion properties of a virtually imaged phased-array etalon using a ray-based, multibounce interference analysis. I demonstrate that the corrected dispersion law is in agreement with the results obtained by paraxial wave theory [Xiao et al., IEEE J. Quantum Electron.40, 420 (2004)].
authors.affiliation: Department of Physics, Duke University, P.O. Box 90305, Durham, North Carolina 27708, USA. gauthier@phy.duke.edu
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Gauthier