title: Optical 90 degree hybrid with broad operating bandwidth of 94 nm.
abstract: We propose an optical 90 degree hybrid where no waveguide intersection in coupling to balanced photodiodes is required for coherent detection. The proposed device consisting of a paired-interference 2x4 multimode interference (MMI) coupler, a phase shifter, and a 2x2 MMI coupler exhibited quadrature phase response over a 94-nm-wide spectral range.
authors.affiliation: Fujitsu Laboratories Ltd., 10-1 Morinosato-Wakamiya, Atsugi 243-0197 Japan. jeong.sh@jp.fujitsu.com
authors.forename: Seok-Hwan
authors.initials: SH
authors.lastname: Jeong
authors.forename: Ken
authors.initials: K
authors.lastname: Morito