DR. ROBERT THOMAS SMITH, D.N.
Medical Practice in Albuquerque, NM

5745630, Apr 28, 1998

Feb 22, 1996

8/603841

Gregory A. Vawter - Albuquerque NM
Robert E. Smith - Albuquerque NM

Sandia Corporation - Albuquerque NM

G02B 610

385129

A cutoff mesa rib waveguide provides single-mode performance regardless of any deep etches that might be used for electrical isolation between integrated electrooptic devices. Utilizing a principle of a cutoff slab waveguide with an asymmetrical refractive index profile, single mode operation is achievable with a wide range of rib widths and does not require demanding etch depth tolerances. This new waveguide design eliminates reflection effects, or self-interference, commonly seen when conventional rib waveguides are combined with deep isolation etches and thereby reduces high order mode propagation and crosstalk compared to the conventional rib waveguides.

6229947, May 8, 2001

Oct 6, 1997

8/944657

Gregory A. Vawter - Albuquerque NM
Robert Edward Smith - Albuquerque NM

Sandia Corporation - Albuquerque NM

G02B 610, G02B 630

385132

A monolithic tapered rib waveguide for transformation of the spot size of light between a semiconductor optical device and an optical fiber or from the fiber into the optical device. The tapered rib waveguide is integrated into the guiding rib atop a cutoff mesa type semiconductor device such as an expanded mode optical modulator or and expanded mode laser. The tapered rib acts to force the guided light down into the mesa structure of the semiconductor optical device instead of being bound to the interface between the bottom of the guiding rib and the top of the cutoff mesa. The single mode light leaving or entering the output face of the mesa structure then can couple to the optical fiber at coupling losses of 1. 0 dB or less.