Berlin 2012 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 86: Semiconductor Lasers

HL 86.4: Talk

Thursday, March 29, 2012, 15:45–16:00, EW 015

MBE-grown InAs/InP-based quantum dot lasers with high modal gain at 1.55 µ emission wavelength — •Christian Gilfert¹, Vitalii Ivanov¹, Johann Peter Reithmaier¹, David Gready², and Gadi Eisenstein² — ¹Technische Physik, Institute of Nanostructure Technologies and Analytics, Universität Kassel, 34132 Kassel, Germany — ²Technion - Israel Institute of Technology, Haifa 32000, Israel

Self-organized InAs/InP(100) quantum dot systems are promising candidates for future telecommunication applications at 1.55 µm. Several groups have reported on a variety of nano species ranging from quantum wires over elongated quantum dashes to quantum dots in this material system. Quantum dots are, however, the preferred choice due to their 0-dimensional confinement. A recently developed growth method allows engineering the shape of the growing species by molecular beam epitaxy. Quantum dot like ensembles exhibiting much smaller photoluminescence line widths than comparable dash structures are achieved. Diode lasers, in which stacks of such structures are used as active region, emit around 1550 nm with good internal characteristics. In particular, a high modal gain of 10 cm⁻¹ per active layer. Consequently, ridge waveguide lasers with 4 active layers could be operated down to cavity lengths as short as 340 µm at room temperature. The threshold current was measured to 35 mA and a cw output power of 16 mW was obtained. Such short cavities are a prerequisite for directly modulated high-speed lasers.