Adiabatic mode converters for photonic integrated circuits and devices

Design details and performance data are presented for (Al,Ga)As and polymeric monolithic tapered rib waveguides achieving modal spot-size transformation for mode-matching from a variety of devices to single-mode optical fiber. 2D expanded output modes of waveguide modulators and lasers are achieved using ID and 2D tapers between non-critical initial and final widths well suited for optical lithography.