Bipolar cascade lasers at emitting wavelengths near 2 /spl mu/m

Near-IR bipolar cascade lasers have recently been investigated [l-51 for some potential advantages such as high output power and increased quantum efficiency compared to conventional diode lasers. A quantum efficiency that may be greater than unity was explicitly pointed out by van der Ziel and Tsang two decades ago [6] when they studied monolithic integrated GaAs diode lasers with tunnel junctions. In this work, we investigate a bipolar cascade laser in the wavelength region of near 2 pm. This wavelength region is important for chemical sensing and wind profile lidar.