Semiconductor waveguide quantum well lasers

Abstract

Coherent laser arrays compatible with silicon photonics are demonstrated in a waveguide geometry in epitaxially grown semiconductor membrane quantum well lasers transferred on substrates of silicon carbide and oxidised silicon; we record lasing thresholds as low as 60 mW of pump power. We study the emission of single lasers and arrays of lasers in the sub-mm range. We are able to create waveguide laser arrays with modal widths of approximately 5-10 µm separated by 10-20 µm, using real and reciprocal space imaging we study their emission characteristics and find that they maintain their mutual coherence while operating on either single or multiple longitudinal modes per lasing cavity.

III-V compound semiconductor membrane quantum well waveguide lasers emitting at 1 μm

“…Threshold values shown in Fig. 4 reach as low as 309 mW, however, 211 mW were achieved on a different area of the sample [3] for a 424 μm long laser cavity. As it is expected from the waveguide configuration, these values are significantly lower than the threshold pump power of ~0.7 W for a MECSEL with the same QW design as our membrane sample [4].…”

“…Reciprocal imaging displayed the interference between the coherent laser emission of the waveguide cavity's end facets. In [3] we demonstrate coherent laser array operation on a SiC substrate recording thresholds down to 60 mW for 70 μm long cavities. Future work will involve micro structuring of the membranes for novel cavity geometries, and the implementation of a spatial light modulator (SLM) to investigate laser arrays by varying pump illumination patterns.…”

“…Membrane external-cavity surface-emitting lasers (MECSELs) were recently developed [2] to demonstrate lasing without a DBR. MECSELs can exhibit edge emitting lasing because the excitonic dipole in a semiconductor QW lies on the plane perpendicular to the growth direction and parallel to the surface of the epitaxial substrate [3]. In this work, we investigate the characteristics of this parasitic effect.…”