title: Design considerations of stacked multilayers of diffractive optical elements for optical network units in optical subscriber-network applications.
abstract: The detailed design process and experimental results of stacked multilayer diffractive optical elements are reported for an optical network unit used in optical subscriber-network applications. The optical network unit accepts two incoming light beams of 1.3- and 1.55-microm wavelengths through a single-mode optical fiber. A laser diode is also placed for bidirectional communications. The optical network unit consists of five diffractive optical elements that perform the following functions: collimation of incoming beams, focusing of the outgoing 1.55-microm beam, 3-dB splitting of the 1.3-microm beam, focusing of the 1.3-microm beam onto the photodiode, and collimation of the light emitted from a laser diode. Possible cost reductions as a result of mass production and the ease of alignment of the stacked diffractive optical elements could be ideal for constructing low-cost optical network units.
authors.affiliation: Semiconductor Technology Laboratory, Oki Electric Industry Company, Ltd., 550-5 Higashiasakawa-cho, Hachioji, Tokyo 193, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sasaki
authors.forename: I
authors.initials: I
authors.lastname: Fukuzaki
authors.forename: Y
authors.initials: Y
authors.lastname: Katsuki
authors.forename: T
authors.initials: T
authors.lastname: Kamijoh