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Continue to ChatLasing-threshold condition for oblique TE and TM modes, spectral singularities, and coherent perfect absorption - https://avesis.istanbul.edu.tr/yayin/f0664e5a-6e46-40ba-8560-f94957510935/lasing-threshold-condition-for-oblique-te-and-tm-modes-spectral-singularities-and-coherent-perfect-absorption