Abstract

The illumination of a plane beneath the radiating aperture of an inclined multimode optical fiber is calculated. Graphical results are presented that show, for a proximal scanning head made up of fiber triplets composed of a central sensing fiber and two illuminating fibers, inclining the illuminating fibers away from the sensing fiber provides improved illumination of the work surface. The improvement in illumination obtained allows closer spacing of the scanning head to the work surface, thus improving resolution. A simple geometrical formula is presented that enables a prediction to be made of the fiber inclination for optimum illumination. This formula holds for large variations in the shape of the fiber polar sensitivity function.

© 1976 Optical Society of America

Resolution of a microscope: improvement using a centrally obstructed condenser aperture and a semitransparent Π-phase annular aperture objective system

V. P. Nayyar and N. K. Verma
Appl. Opt. 15(5) 1341-1344 (1976)

Optical proximity sensor that uses a laser-scanning system

Junichi Kurata, K. T. V. Grattan, Hironobu Uchiyama, and Teruo Tanaka
Appl. Opt. 30(28) 4060-4065 (1991)

Multimode optical waveguides with graded refractive index: theory of power launching

P. Di Vita and R. Vannucci
Appl. Opt. 15(11) 2765-2772 (1976)

Analytical illuminance and caustic surface calculations in geometrical optics

David L. Shealy
Appl. Opt. 15(10) 2588-2596 (1976)

Multimode optical fibers: interplay of absorption and radiation losses

Colin Pask and Allan W. Snyder
Appl. Opt. 15(5) 1295-1298 (1976)