An optimized N×N planar optic star coupler that utilizes directional coupling of arrayed waveguides for uniform power splitting is analyzed on the basis of special properties of the involved Bessel-function series. The analysis has provided a remarkably simple, novel basic design formula for such a device with much needed physical insights into the unique diffraction properties. For the analysis of diffraction from the end of directionally coupled arrayed waveguides, many useful formulas around the Bessel functions, such as the addition theorem and the Kepler–Bessel series, have been given in new forms.
© 2004 Optical Society of America
(050.0050) Diffraction and gratings : Diffraction and gratings
(130.0130) Integrated optics : Integrated optics
(230.3120) Optical devices : Integrated optics devices
(230.7390) Optical devices : Waveguides, planar
G. Hugh Song and Mahn Yong Park, "Bessel-function analysis of the optimized star coupler for uniform power splitting," J. Opt. Soc. Am. A 21, 1529-1544 (2004)