SINGLE-TRANSVERSE-MODE INGAASP-INP EDGE-EMITTING BIPOLAR CASCADE LASER
11 January 2005
In order to improve the radio frequency (RF) link gain of opto-RF links, we have designed, fabricated, and characterized a bipolar cascade laser (BCL). It includes two active regions and one highly doped backward-biased tunnel junction. In order to study the intrinsic properties, we have etched a 18 µm-wide deep-ridge. Comparing the result with a similar structure that does not recycle the carriers, we found an increase by a factor of two of the internal quantum efficiency. The same structure was etched into a 2.5 µm-wide shallow ridge laser. We demonstrate a single-transverse-mode edge-emitter 1.55 µm BCL with enhanced external efficiency, paving the way to short term opto-RF system characteristics improvement.