Fabrication of narrow-striped InAs/GaAs quantum dot laser with wet etching technique

Abstract

An InAs/GaAs quantum dot laser, fabricated with a narrow-striped width of 6 μm by a wet etching technique, is reported. The etching solutions are composed of three components, i.e. phosphoric acid, hydrogen peroxide, and deionized water. We observed that the unavoidable undercutting was changed with the ratio of etching solution in the GaAs materials. By taking a suitable ratio of etching solution, good performance of quantum dot laser with a size of 6 μm × 700 μm was achieved for fabrication at room temperature. Under continuous wave mode, the lasing wavelength exhibited a single mode, which is located in the region of 1051 nm. In contrast, multimode lasing with a series of non-lasing gaps appeared and the spectra were gradually broadened to the high energy side by increasing the injection current. The laser has one facet power more than 22 mW, with a slope efficiency of 140 mW/A, just a little above threshold current.

Keywords:

• semiconductor laser
• quantum dot laser
• gallium arsenide
• gas source molecular beam epitaxy

Acknowledgements

This work is financially supported by the National Natural Foundation of China (Grant Nos. 61204058, 10990103, 61021064 and 61240015) and by the Foundation of Shenzhen Innovation Program (Grant No. JCYJ20130401095559823).