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arXiv · 1501.06767

Lasing Threshold Condition for Oblique TE and TM Modes, Spectral Singularities, and Coherent Perfect Absorption

Ali Mostafazadeh·Mustafa Sarisaman
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Abstract

We study spectral singularities and their application in determining the threshold gain coefficient $g^{(E/M)}$ for oblique transverse electric/magnetic (TE/TM) modes of an infinite planar slab of homogenous optically active material. We show that $g^{(E)}$ is a monotonically decreasing function of the incidence angle $θ$ (measured with respect to the normal direction to the slab), while $g^{(M)}$ has a single maximum, $θ_c$, where it takes an extremely large value. We identify $θ_c$ with the Brewster's angle and show that $g^{(E)}$ and $g^{(M)}$ coincide for $θ=0$ (normal incidence), tend to zero as $θ\to 90^\circ$, and satisfy $g^{(E)} θ_c$ is smaller inside the gain region than outside it. The converse is true for the TM waves with $θ<θ_c$ and all TE waves.

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Ali Mostafazadeh, Mustafa Sarisaman. 2015-01-27. Lasing Threshold Condition for Oblique TE and TM Modes, Spectral Singularities, and Coherent Perfect Absorption. https://doi.org/10.1103/physreva.91.043804

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