Spectral singularities, threshold gain, and output intensity for a slab laser with mirrors

We explore the consequences of the emergence of linear and non-linear spectral singularities in TE modes of a homogeneous slab of active optical material that is placed between two mirrors. We use the results together with two basic postulates regarding the behavior of laser light emission to derive explicit expressions for the laser threshold condition and output intensity for these modes of the slab and discuss their physical implications. In particular, we reveal the details of the dependence of the threshold gain and output intensity on the position and properties of the mirrors and on the real part of the refractive index of the gain material. (C) 2018 Elsevier Inc. All rights reserved.