title: Quadrature outputs from fiber interferometer with 4 x 4 coupler.
abstract: A broad stripe waveguide of width W and length L acts as a self-imaging 4 x 4 directional coupler if L = NW(2)/lambda, where N is the effective index. When the arms of a fiber-optic Mach-Zehnder interferometer are connected to two input ports of this coupler, the powers at the four output ports vary in phase quadrature.
authors.forename: T
authors.initials: T
authors.lastname: Niemeier
authors.forename: R
authors.initials: R
authors.lastname: Ulrich