Low frequency noise study for developing of AlGaAs and GaAsBi QW structures for NIR LDs

Low noise characteristics of Fabry-Perot type laser diodes emitting at (780 – 1100) nm wavelengths were investigated for optimization of geometry and composition of the active layer. The laser structures, consisted of (Al,Ga)As and Ga(As,Bi) rectangular or parabolic quantum wells in the active area, were grown by the molecular beam epitaxy on the n-type GaAs(100) substrate. The photolithography was performed to fabricate the edge emitting laser bars of 5 μm to 500 μm in size. The characteristic LD threshold current varied in the range of (60-120) mA. Low frequency optical and electrical noise spectra have been measured in temperature range from 70 K to 290 K and comprised of 1/f and Lorentzian type components. The positive cross-correlation between optical and electrical fluctuations was observed.