ABSTRACT
Ternary semiconductors like GaInP under certain growth conditions exhibit a (partial) chemical ordering in form of a superlattice of alternate Ga-rich and In-rich planes in (11̄1) direction. We have studied the polarization properties of light propagating in ordered GaInP/AlGaInP waveguide structures. For the first time, we have observed mode-conversion between transverse electric (TE) and transverse magnetic (TM) modes within typically 60μm in such structures. We show that the reduced symmetry of the ordered material leads to an optical birefringence with the axis tilted with respect to the growth direction and therefore to a coupling between the TE and the TM mode.
