[OPTICAL REVIEW Vol. 3, No. 2 (1996) 109-113]

Field Analysis of Pillbox Resonator with Radiation Loss Utilizing Finite-Element Beam Propagation Method Formulation

Anis AHMED, Ryuichi KOYA, Osami WADA, Ming WANG and Ryuji KOGA

Faculty of Engineering, Okayama University, Tsushima-naka, 3-1-1, Okayama, 700 Japan

(Received August 7, 1995; Accepted December 12, 1995)

To deal with the radiation from an axially symmetric pillbox resonator embedded in LiNbO3 substrate, an eigenvalue equation is derived from the expression of the finite-element beam propagation method in a cylindrical coordinate system. By solving the eigenvalue equation iteratively, the field distributions and the angular phase constants of the pillbox resonator are evaluated. The iterative scheme of solving the eigenvalue equation is an extension of our previous direct solution method which was described for a lossless case. The results obtained by this method are compared with those obtained analytically, and excellent agreement is found.

Key words : optical integrated circuit, pillbox resonator, whispering gallery mode, radiation loss