Coupling of low-order LP modes propagating in cylindrical waveguides into whispering gallery modes in microspheres.
Whispering gallery modes in microspheres are excited by light delivered to them via optical fibers imbedded in a half-block coupler. The corresponding light intensity resonances in microspheres and coupling of two low-order linearly polarized modes in the fibers, LP₀₁ and LP₁₁, into the microspheres are observed. The LP₀₁ and LP₁₁ modes are delivered to the microsphere via a cylindrical optical fiber carrying light at two operating wavelengths, 1550 and 1300 nm correspondingly. The resonances behavioral differences generated by these fiber modes are also observed and explained. The properties of resonances generated by the LP₀₁ and LP₁₁ modes are analyzed using a linear polarizer inserted in the path of light propagating in optical fibers.