Abstract

Certain advantages such as improved polarization-sensitivity and frequency chirping can be anticipated if curved electrodes are used in activation of the quantum-well material of intersecting waveguide type optical switches/modulators [1,2]. However, since semiconductors are used, the propagation loss is an important issue and one is concerned with absorption losses. In this respect, curved electrodes are shown to reduce light absorption associated with refractive index changes, remarkably. Fig. 1 shows an intersecting waveguide switch/modulator where a curved electrode of length I is used in application of the signal voltage to the semiconductor material. The guided mode is taken as the superposition of differently oriented plane-wave components impinging on the electrode. The propagation distance of each plane wave is estimated and used in calculation of the absorption loss. Fig. 2 shows the light absorption losses in the semiconductor material of quantum-well structure under the straight and curved electrodes versus the distance of the main component to the electrode ρ₀ (shown in Fig. 1).

© 2001 EPS