GaAs/GaAlAs graded refractive-index embedded core optical waveguides by OMCVD

A description is given of graded refractive-index embedded core optical (GRECO) waveguides produced in GaAs/GaAlAs by sequential introduction of varying numbers of superlattice periods during metallorganic chemical vapor deposition (MOVCD) growth of the GaAs core material on patterned substrates. This technique offers the possibility of synthesizing the vertical index profile of the core and provides a built-in index difference for lateral confinement of guided modes. Fully planarized embedded waveguides fabricated with propagation losses of 1.5 dB/cm at a wavelength of 1.523 mu m are reported; their field distribution was analyzed using a finite-element technique. >