Abstract
We study the formation of longer-lived states via internal coupling near a special avoided resonance crossing between the interacting states in an open optical system. Away from the parity-time symmetry limit, we discuss unconventional cavity resonance states created by a spatially varying gain/loss profile. Now, via S-matrix formalism, we have numerically demonstrated that with suitably chosen system openness and coupling strengths, the excess noise generation among the interacting nonorthogonal states (calculated as Petermann factor K) can be suppressed close to the ideal value of one with a simultaneous order of magnitude enhancement in the quality-factor of the longer-lived state. (C) 2016 Optical Society of America