Quantum dot (QD) lasers have many attractive features including low-threshold current density, high gain, low chirp and superior temperature stability. In this paper, design, fabrication and characteristics of wafer-level index coupled holographically fabricated 1.3μm QD distributed feedback (DFB) lasers are reported. Previously, 1.3 μm QD-DFB lasers were fabricated with metal surface gratings, which are lossy and (being typically written by e-beam lithography) are difficult to fabricate. In this paper, devices are fabricated using molecular beam epitaxy (MBE) for QD growth, metalorganic chemical vapor deposition (MOCVD) for grating overgrowth, and wafer level interference lithography for grating fabrication. Design and fabrication methods for these devices are reported. Analysis of broad area devices gives a material transparency current density of ~150A/cm². Single mode ridge waveguide devices with cavity length of 500 μm were tested. Device characteristics were fairly uniform, with typical DC characteristics of the devices of threshold currents of ~35mA and slope efficiencies of ~0.11W/A. Measured bandwidths at room temperature were around 1.5 GHz, with very flat responses. Further analysis and design revision of the laser is ongoing.

Date Published: 16 February 2011
PDF: 7 pages
Proc. SPIE 7953, Novel In-Plane Semiconductor Lasers X, 795309 (16 February 2011); doi: 10.1117/12.873605

Published in SPIE Proceedings Vol. 7953:
Novel In-Plane Semiconductor Lasers X
Alexey A. Belyanin; Peter M. Smowton, Editor(s)