Measurement of output phase relationships of multimode interference splitters using a shearing-type near-field Sagnac interferometer

摘要

Multimode interference (MMI) devices, based on the self-imaging effect, exhibit low excess loss, ultra-compact size, wavelength and polarization insensitivity. These desirable characteristics make MMI splitters/combiners very attractive for wavelength division multiplexing (WDM) applications. A complete study of the phase behavior of MMI devices has to be undertaken to investigate the use of these devices in optical interference based WDM applications. A comprehensive theoretical analysis of phase relations for a general N/spl times/N MMI coupler has been reported by M. Bachmann et al.{ see, Appl. Opt., vol. 33, p. 3905, 1994}. Here, we report the experimental measurement of the output phase relationships of AlGaAs-GaAs MMI waveguide splitters, using a ring interferometer.