Title :
A new design approach to large input/output number multimode interference couplers and its application to low-crosstalk WDM routers
Author :
Huang, J.Z. ; Scarmozzino, R. ; Osgood, R.M., Jr.
Author_Institution :
Microelectron. Sci. Lab., Columbia Univ., New York, NY, USA
Abstract :
A new design approach for N/spl times/N multimode interference (MMI) couplers with large N is described which yields a device design with extremely low imbalance and insertion loss. Analytical expressions for the phase errors in MMI devices are derived from basic principles; these expressions enable significant phase-error reduction to be obtained by optimizing the index-contrast. This optimization in conjunction with the proper placement of the access waveguides allows significant improvement in the device performance. An application of the design approach is illustrated through the design of an 8/spl times/8 MMI-based, phased-array demultiplexer with low crosstalk.
Keywords :
arrays; demultiplexing equipment; integrated optics; light interference; optical communication equipment; optical couplers; optical crosstalk; optical design techniques; optimisation; telecommunication network routing; wavelength division multiplexing; 8/spl times/8 MMI-based phased-array demultiplexer; MMI devices; access waveguides; device performance; extremely low imbalance; index-contrast; insertion loss; large input/output number multimode interference coupler design; low crosstalk; low-crosstalk WDM routers; phase errors; phase-error reduction; Couplers; Crosstalk; Insertion loss; Interference; Optical imaging; Optical signal processing; Optical waveguides; Photonic integrated circuits; Propagation constant; Wavelength division multiplexing;
Journal_Title :
Photonics Technology Letters, IEEE
