This paper summarizes recent advances on InAs/InP quantum dashes (QD) materials for lasers and amplifiers, and QD device performance with particular interest for optical communication. We investigate both InAs/InP dashes in a barrier and dashes in a well (DWELL) heterostructures operating at 1.5 µm. These two types of QDs can provide high gain and low losses. Continuous-wave room-temperature lasing operation on ground state of cavity length as short as 200µm has been achieved, demonstrating the high modal gain of the active core. A threshold current density as low as 110 A/cm 2 per QD layer has been obtained for infinite-length DWELL laser. An optimized DWELL structure allows achieving of a T0 larger than 100 K for broad area lasers and of 80 K for single transverse mode lasers in the temperature range between 25°C and 85°C. Buried ridge stripe type single mode DFB lasers are also demonstrated for the first time, exhibiting a side-mode suppression-ratio as high as 45 dB. Such DFB lasers allow the first floor free 10 Gb/s direct modulation for back-to-back and transmission over 16 km standard optical fiber. In addition, novel results are given on gain, noise and four wave mixing of QD-based semiconductor optical amplifiers. Furthermore, we demonstrate that QD FP lasers, owing to the small confinement factor and the 3D quantification of electronic energy levels, exhibit a beating linewidth as narrow as 15 kHz. Such an extremely narrow linewidth, compared to their QW or bulk counterparts, leads to the excellent phase noise and time jitter characteristics when QD lasers are actively mode-locked. These advances constitute a new step towards the application of QD lasers and amplifiers to the field of optical fiber communications.

Abstract:A heterogeneously integrated III-V-on-silicon laser is reported, integrating a III-V gain section, a silicon ring resonator for wavelength selection and two silicon Bragg grating reflectors as back and front mirrors. Single wavelength operation with a side mode suppression ratio higher than 45 dB is obtained. An output power up to 10 mW at 20 ⁰C and a thermooptic wavelength tuning range of 8 nm are achieved. The laser linewidth is found to be 1.7 MHz.

Abstract-We report on a heterogeneously integrated InP/SOI laser source realized through DVS-BCB wafer bonding. The hybrid lasers present several new features. The III-V laser is only 1.7μm wide, reducing the power consumption of the device. The silicon waveguide thickness is 400 nm, compatible with highperformance modulator designs and allowing efficient coupling to a standard 220nm high index contrast silicon waveguide layer. In order to make the mode coupling efficient, both the III-V waveguide and silicon waveguide are tapered, with a tip width for the III-V waveguide of around 800 nm. These new features lead to good laser performance: a lasing threshold as low as 30mA and an output power of more than 4mW at room temperature in continous wave operation regime. Continuous wave lasing up to 70C is obtained.Index Terms-Hybrid integrated circuits, silicon laser, silicon-on-insulator (SOI) technology, adiabatic taper.