AM and FM quantum noise in semiconductor lasers - Part II: Comparison of theoretical and experimental results for AlGaAs lasers

Four different theoretical formulations for AM and FM quantum noise properties in semiconductor lasers are compared with each other for AlGaAs lasers. These formulations are based on van der Pol, Fokker-Planck, rate, and photon density matrix equations. Experimental results with AM noise spectra, FM noise spectra, and spectral linewidths for four different types of AlGaAs lasers are also delineated and compared with the theoretical predictions. The spontaneous emission coefficient β and population inversion parameter nsp, which are basic parameters for determining the quantum noise properties of semiconductor lasers, were calculated by the density of states with Kane function interpolated to Halperin-Lax bandtail and the Stern´s improved matrix element. Experimental AM and FM quantum noise properties show good agreement with the theoretical predictions derived through use of estimated β and nspvalues.