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qcl:optics

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Optics: gain/absorption calculation

Permittivity

The bulk relative permittivity, or dielectric constant, is assumed to be given by the Lyddane–Sachs–Teller relation:

$$ \epsilon_{\text{bulk}}(\omega) = \epsilon_{\infty} + (\epsilon_{\infty}-\epsilon_{\text{static}}) \frac{\omega_{\text{TO}}}{\omega^2-\omega^2_{\text{TO}}}$$

In the self-consistent gain calculation, the quantity which is actually calculated is the a.c. conductivity $\sigma(\omega)$.

The complex permittivity which is output is then:

$$ \epsilon(\omega) = \epsilon_{\text{bulk}}(\omega) - i \frac{\sigma(\omega)}{\omega \epsilon_0} $$

qcl/optics.1599580071.txt.gz · Last modified: 2020/09/08 15:47 by thomas.grange