HIGH-TEMPERATURE OPERATION OF ALGAINAS INP LASERS 1994/

We discuss the design of uncooled lasers which minimizes the change in both threshold current and slope efficiency over the temperature rang e from -40 to +85 degrees C [1]. To prevent carrier overflow under hig h-temperature operation, the electron confinement energy is increased by using the Al(x)Ga(y)ln(1-x-y)As/lnP material system [1] instead of the conventional Ga(x)ln(1-x)As(y)P(1-y)/lnP material system. Experime ntally, we have investigated strained quantum well lasers with three d ifferent barrier layers and confirmed that the static and dynamical pe rformance of the lasers with insufficient carrier confinement degrades severely under high-temperature operation [2]. With an optimized barr ier layer, the AI(x)Ga(y)ln(1-x-y)As/lnP strained quantum well lasers show superior high-temperature performance, such as a small drop of 0. 3 dB in slope efficiency when the heat sink temperature changes from 2 5 to 100 degrees C [3], a maximum CW operation temperature of 185 degr ees C [4], a thermally-limited 3-dB bandwidth of 13.9 GHz at 85 degree s C [2], and a mean-time-to-failure of 33 years at 100 degrees C and 1 0 mW output power [5].