We report on GaAs-based broad area (100 µm) 1.3 µm quantum dot (QD) lasers with high CW output power (5 W) and wall-plug efficiency (56%). The reliability of the devices has been demonstrated beyond 3000 h of CW operation at 0.9 W and 40 • C heat sink temperature with 2% degradation in performance. P-doped QD lasers with a temperature-insensitive threshold current (T 0 > 650 K) and differential efficiency (T 1 = infinity) up to 80 • C have been realized.

We report on a quantum dot laser having an emission spectrum as broad as 74.9 nm at 25 degrees C in the 1.2-1.28 wavelength interval with a total pulsed output power of 750 mW in single lateral mode regime and the average spectral power density of >10 mW/nm. A significant overlap and approximate equalization of the ground-state and the excited-state emission bands in the laser's spectrum is achieved by means of intentional inhomogeneous broadening of the quantum dot energy levels.

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Measurements of saturated amplified spontaneous emission-spectra of quantum dot semiconductor optical amplifiers demonstrate efficient replenishment of the quantum-dot ground state population from excited states. This saturation behavior is perfectly modeled by a rate equation model. We examined experimentally the dependence of saturation on the drive current and the saturating optical pump power as well as on the pump wavelength. A coherent noise spectral hole is observed with which we assess dynamical properties and propose optimization of the SOA operating parameters for high speed applications.

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Wavelength-stabilized operation is realized in broad area quantum dot laser diodes with cleaved facets grown in the tilted cavity laser (TCL) design for the range up to 1.3 µm. For two different designs TCL wavelength is chosen to be either in the range of quantum dot excited state transitions (1.16 µm), or in the range of quantum dot ground state transitions (1.27 µm). The shift of the lasing wavelength is 0.165 nm K −1 in a temperature range between −200 • C and 70 • C. The spectral width of the lasing emission in broad area devices is 0.6 nm and the width (FWHM) of the far field is 4 • and 42 • for lateral and vertical directions, respectively.

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We demonstrate concurrent multi-channel transmission at 10 Gbps per channel of a DWDM silicon photonic transmitter. The DWDM transmitter is based on a single quantum dot comb laser and an array of microring resonator-based modulators. The resonant wavelengths of microrings are thermally tuned to align with the wavelengths provided by the comb laser. No obvious crosstalk is observed at 240 GHz channel spacing.