Quantum well vertical light modulator

A waveguide modulator is proposed whose operation is based on the dissipative coupling of light from a waveguide into an appropriate quantum-well structure. This approach uses the electric-field-induced change of the refractive index for light modulation. A particular geometrical configuration is numerically evaluated. The advantages of this configuration are that the combination of high switching speed ( approximately=1 ps), high on/off ratios (e.g. 1/16 dB or 2/25 dB), and low-driving voltage (4 V) could be combined in one device. The proposed modulator exhibits negligible phase shifts when the attenuation is smaller than about 10 dB.<>