Thresholds of Lasing as Solutions of Characteristic Equation for a VCSEL-type Layered Structure

Thresholds of lasing for a cavity with a quantum well placed between two distributed Bragg reflectors are investigated as a specific eigenvalue problem with "active" imaginary part of the quantum well refractive index. The characteristic equation is obtained from the transmission-matrix formalism. Preliminary results show that the frequencies of lasing are determined mainly by the size and material of the cavity, and the thresholds are sensitive to the quantum-well size and location and can be lowered by the proper tuning of the Bragg reflectors.