Abstract

We report the first colinear single-mode polymer waveguide modulator that can be formed on any smooth surface—including semiconductors, conductors, and insula tors—regardless of its conductivity and refractive index. The tunability of polymer film allows us to shift the guiding layer from step index profile to graded-index profile. The phase-matching condition for optical power transfer is achieved through current injection. A 34 dB extinction ratio was observed with an injection current density of ~10 μA/μm2. Unlike that of the conventional dual-channel coupler, the asymmetry of the colinear waveguide pair provides us with a much larger dynamic range of waveguide dimensions, and, thus, eases the requirements of waveguide fabrication.

© 1990 Optical Society of America