Results of a rigorous leaky wave analysis of an optical grating coupler having a large grating period are presented. The coupler is designed so that most of the guided-wave power is transferred to a substrate beam progressing in the forward direction with the first-order air beam made evanescent. It is found that a large power partition into the substrate beam can readily be obtained in spite of the presence of a number of higherorder propagating space harmonics. Validity of the approximate perturbation method for the case of the long grating period is also examined.
© 1989 Optical Society of America
Masayuki Matsumoto, Manabu Ohtsuka, and Masanori Matsuhara, "Leaky wave analysis of an optical grating coupler with a large grating period," Appl. Opt. 28, 2039-2042 (1989)