In the electro-optic waveguide switch shown in the figure, how large a voltage (V) must be applied to the electrode to turn the waveguide on – i.e., to increase the index of refraction in the...

In the electro-optic waveguide switch shown in the figure, how large a voltage

(V) must be applied to the electrode to turn the waveguide on – i.e., to increase

the index of refraction in the waveguide sufficiently so as to bring it above

cutoff for the lowest order waveguide mode?

Assume:

(1) Wavelength of light in air λ0 = 1.0 μm.

(2) Effective mass of electron m∗ = 0.08me.

(3) All of the voltage is dropped over the waveguide thickness rather than in

the substrate.