The emission of light from whispering-gallery modes excited in microscopic spheres is examined. An evanescent wave is produced by total internal reflection of an optical beam at a planar glass–air interface. This evanescent wave is used to excite whispering-gallery modes in single microscopic spheres placed behind the glass–air interface. The intensity of light emitted into the air half-space from such spheres is measured as a function of scattering angle for both <i>p</i>- and <i>s</i>-polarized input beams. These data are compared with a simple theory for the emission from a point source above a planar glass substrate.
© 2003 Optical Society of America
Michael J. Jory, Elaine A. Perkins, and J. Roy Sambles, "Light emission from whispering-gallery modes in microscopic spheres," J. Opt. Soc. Am. A 20, 1785-1791 (2003)