Amplified spontaneous emission and threshold crossing in a distributed-Bragg reflector grating-coupled surface-emitting laser

Threshold crossing and spectral properties of a curved-grating distributed Bragg reflector quantum-well laser (c-DBR)

“…where P is the pumping rate (m −3 s −1 ), R(N) = A nr N + B sp N 2 + C Au N 3 the non-radiative, spontaneous and Auger recombination rate, respectively, whereas R ASE (N) is the recombination stimulated by ASE, itself proportional to the total saturating intensity I SAT , averaged spatially from ρ 1 to ρ 2 along the active zone and integrated analytically over its whole Lorentzian-like spectral range [11,12]. In the steadystate regime, dN/dt = 0, so that…”

Near-threshold spectral and modal characteristics of a curved-grating quantum-well distributed-feedback laser

“…As a matter of fact, we should take account of the saturation of the gain medium through amplified spontaneous emission (ASE), which is considered as the driving source of the optical field and projected into the mode. We shall see now how the extended matrix formalism can be used to derive an expression for the linewidth that remains continuously valid across the threshold [9,10].…”