Bend loss of slab and fiber modes computed with diffraction theory

Radiation losses from optical waveguides that are bent into a circle are calculated with the help of Fraunhofer's diffraction theory. The validity of the result is tested by showing that it is in agreement with the known bend loss formulas of the slab waveguide of the LP/sub 01/-mode of the round step-index fiber. The accuracy of the bend loss calculations is limited by the use of a scalar theory to approximate a vector problem and by additional mathematical approximations that are required to solve an integral.<
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