PROCEEDINGS ARTICLE | February 3, 2009
Proc. SPIE. 7230, Novel In-Plane Semiconductor Lasers VIII
KEYWORDS: Transparency, Continuous wave operation, Modulation, Waveguides, Electrodes, High power lasers, Semiconductor lasers, Near field, Internal quantum efficiency, Free space optical communications
High-brightness diode lasers at 1060 nm are useful in display applications (to provide green light by frequency doubling)
and in free-space optical communications. On Al-free active region laser structures, we have obtained low optical losses
of 0.9 cm<sup>-1</sup>, a high internal quantum efficiency of 98% and a low transparency current density of 64 A/cm<sup>2</sup>. On uncoated
broad-area lasers (2 mm x 100 μm) at 20°C CW, we have obtained a high maximum wall-plug efficiency of 66%, and an
optical power higher than 3W per facet.
Based on these good results, we have realized 3.7 mm long gain-guided tapered lasers, delivering a high power of 3W at
10°C CW, together with a low M<sup>2</sup> of 3 at 1/e<sup>2</sup> and a high maximum wall-plug efficiency of 57%.
We have also realized separate electrode lasers, in which the ridge and tapered sections are biased separately. In this
configuration, the current through the ridge section is only a few tens mA while the current on the tapered section is
several Amps. This allows to control a large output power with only a small change of the ridge current. By moving the
ridge current from 0 to 50 mA, keeping a constant 4A current through the tapered section, we have obtained a large
change of the output power from 0.09 W to 2.6 W, which corresponds to a high modulation efficiency of 50 W/A under
static operation. In dynamic regime, the separate electrode laser can be operated at 700 Mbps, showing a high
modulation efficiency of 19 W/A, optical modulation amplitude of 1.6 W and extinction ratio of 19dB [1]. These
modulation efficiencies are, to our knowledge, record values.
