title: Use of retinal nerve fiber layer birefringence as an addition to absorption in retinal scanning for biometric purposes.
abstract: We built a device sensitive to the birefringence of the retinal nerve fiber layer for biometric purposes. A circle of 20 degrees diameter on the retina was scanned around the optic disk with a spot of light from a 785 nm laser diode. The nonbirefringent blood vessels indenting or displacing the retinal nerve fiber layer were seen as "blips" in the measured birefringence-derived signal. For comparison, the reflection-absorption signature of the blood vessel pattern in the scanned circle was also measured. The birefringence-derived signal proved to add useful information to the reflectance-absorption signature for retinal biometric scanning.
authors.affiliation: Kirchhoff Institut für Physik, University of Heidelberg, INF 227, 69120 Heidelberg, Germany. mikael.agopov@iki.fi
authors.forename: Mikael
authors.initials: M
authors.lastname: Agopov
authors.forename: Boris I
authors.initials: BI
authors.lastname: Gramatikov
authors.forename: Yi-Kai
authors.initials: YK
authors.lastname: Wu
authors.forename: Kristina
authors.initials: K
authors.lastname: Irsch
authors.forename: David L
authors.initials: DL
authors.lastname: Guyton
mesh_terms: D000042:Absorption; D001699:Biometry / Q000295:instrumentation* / Q000379:methods*; D001718:Birefringence; D004867:Equipment Design; D006801:Humans; D008027:Light; D009898:Optic Disk / Q000473:pathology; D009900:Optic Nerve / Q000473:pathology*; D055095:Optics and Photonics; D012160:Retina / Q000473:pathology*; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods