Cost effective lasers meeting the linewidth requirements for coherent communication systems are a key element in reducing the overall cost of future coherent systems. We report on monolithic devices with linewidths as low as 138 kHz which operate in a narrow linewidth, single wavelength mode with high sidemode suppression ratio over a wide temperature tuning range of -10°C < T < 110°C. A linewidth variation of only 23 kHz was measured at a constant emitted power of 4 mW as the device temperature is varied in the range 0°C < T < 85 °C. © 2011 Optical Society of America.