We examine the structure and modal gains of the leaky modes of an infinite periodic index-guided array by direct solution of the two-dimensional Helmholtz equation. These findings serve to validate the physical insights suggested by our previous calculations based on the effective-index method and, in particular, confirm the concept of guide-width tailoring for affecting fundamental-mode operation of these devices at high power levels. Our newer model also provides new insights into the mode-selection mechanism and demonstrates clearly the necessity of a full two-dimensional treatment if one is to describe the mode profiles or their relative gains accurately.
© 1989 Optical Society of America
Original Manuscript: February 15, 1989
Manuscript Accepted: May 23, 1989
Published: August 15, 1989
G. Ronald Hadley, "Two-dimensional waveguide modeling of leaky-mode arrays," Opt. Lett. 14, 859-861 (1989)