Semiconductor Waveguide Switches and Modulators,
Abstract
Many people think that the electrooptic properties of GaAs and InP are inferior to those in LiNbO3. This is not the case. It is true that the linear electrooptic coefficient r is much smaller in these semiconductors than in LiNbO3. However, the refractive index n is much larger, and the relative permittivity epsilon sub r, is much smaller. As a result, the most important figure of merit PI A/delta f (modulating power/bandwidth), which is proportional to er/n6r2 in waveguide modulators, in GaAs or InP is comparable to that in LiNbO3, in the wavelength region 1-1.6um. Besides the linear electrooptic (Pockels) effect, a variety of physical phenomena in these materials resulting in changes of the refractive index and the absorption coefficient can be utilized to build fast and compact modulators/switches.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1992
- Accession Number
- ADP008013
Entities
People
- Kunio Tada
Organizations
- University of Tokyo