We demonstrate a new scheme to enhance the spatial resolution of a confocal optical microscope. Our scheme improves the spatial resolution in the direction of the optical axis. The confocal optical microscope, by use of a four-wave mixing geometry, can obtain optical information about weakly absorptive objects with organic dyes. Owing to the third-order nonlinear dependence of absorptive objects, the optical signal is confined to the focal region of the focusing incident beam.
© 2006 Optical Society of America
Original Manuscript: August 19, 2005
Revised Manuscript: November 28, 2005
Manuscript Accepted: December 7, 2005
Vol. 1, Iss. 4 Virtual Journal for Biomedical Optics
Chikara Egami, Naoki Kobayashi, Yoshimasa Kawata, and Minoru Masaki, "Confocal nonlinear optical microscopy for high-resolution measurement of absorptive objects," Opt. Lett. 31, 784-786 (2006)