Slow wave electrooptic light modulators
The goal of this research is to show that novel modulator designs incorporating optical feedback can greatly improve the efficiency and linearity of high-speed optical modulators. Slow wave modulators are being fabricated in lithium niobate (LiNbO3) substrates using titanium diffusion to form single mode optical waveguides, with metal electrodes on the surface to apply electrical modulation, and photonic bandgap gratings on the optical waveguides to slow down the light propagation, as shown in Fig. 1. Nanolithography is needed to define precise grating structures, which provide high reflectance and low optical loss as required for high-performance modulators. This project has created significant industrial interest from the 3M optoelectronics division.
Figure 1. Slow wave electrooptic light modulator.