A holographic fingerprint sensor has been developed for a system that identifies a person by his or her fingerprints. The sensor uses a laser as its light source and consists of a light-conducting plate, which is a transparent glass plate with a plain grating-type hologram, and a focusing lens system just under the hologram. Since the sensor uses a plane-parallel plate, all the optical paths from each point of a fingerprint to the hologram are equal, and a bright fingerprint can be created without the trapezoidal distortion that is inherent in conventional prism-type sensors.
© 1992 Optical Society of America
Original Manuscript: May 26, 1989
Published: April 10, 1992
Seigo Igaki, Shin Eguchi, Fumio Yamagishi, Hiroyuki Ikeda, and Takefumi Inagaki, "Real-time fingerprint sensor using a hologram," Appl. Opt. 31, 1794-1802 (1992)