Understanding AC and Optical Conductivity: Conflicting Information Clarified

[DeathbyGreen]

Maybe someone can help me out; I've been seeing conflicting information on the meaning behind optical conductivity vs AC conductivity. Some papers seem to post plots of transmission and reflectivity, and others a Drude-like \sigma(\omega). In many textbooks I can't seem to find a satisfactory answer.

If we start with a system under a field E(t) = Ee^{i\omega t}, solve the Drude model to get \sigma(\omega), is this an expression for optical conductivity or AC? And what are the geometries of both?

 

[DrDu]

If we start with a system under a field E(t) = Ee^{i\omega t}, solve the Drude model to get \sigma(\omega), is this an expression for optical conductivity or AC? And what are the geometries of both?

I think this depends on frequency (radio- vs. optical).

 

[Chandra Prayaga]

By optical conductivity, do you mean photo-conductivity, which is a material becoming conducting when exposed to light, or do you just mean conductivity at very high frequencies?

 

[DeathbyGreen]

I mean conductivity induced by irradiation; I've seen this called both optical and AC conductivity. Maybe it's just called AC because the light has a frequency and an analogy can be drawn between that and actual AC electricity with connected leads?