Title :
Epitaxially-stacked multiple-active-regions for high differential efficiency monolithic 1.55 /spl mu/m VCSELs
Author :
Kim, J.K. ; Hall, E. ; Sjolund, O. ; Coldren, L.A.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Santa Barbara, CA, USA
Abstract :
The development of monolithic 1.55 /spl mu/m VCSELs has been hampered by the lack of readily available highly reflective DBRs. However, it is possible to achieve lasing with less reflective DBRs by epitaxially stacking multiple active regions and increasing the gain. For example, 30.5-period AlGaInAs/AlInAs DBRs can be mated to a three-stage active region to achieve lasing. Epitaxy of such VCSEL can be short enough to maintain source stability in an MBE system. The other benefit is greater differential efficiency, which can actually exceed unity, for greater signal to noise ratio. We have investigated the properties of such active regions. We have created edge-emitters with external differential efficiencies >1 by monolithically connecting several active regions in series within a single optical waveguide. In contrast to previous reports, we have accomplished this task at the technologically important 1.55 /spl mu/m wavelength.
Keywords :
III-V semiconductors; aluminium compounds; distributed Bragg reflector lasers; gallium arsenide; indium compounds; laser beams; laser cavity resonators; laser noise; molecular beam epitaxial growth; optical fabrication; ridge waveguides; semiconductor lasers; surface emitting lasers; waveguide lasers; 1.55 mum; AlGaInAs-AlInAs; AlGaInAs/AlInAs; MBE system; active regions; differential efficiency; differential efficiency monolithic VCSELs; distributed Bragg reflectors; edge-emitters; epitaxially-stacked multiple-active-regions; epitaxy; external differential efficiencies; gain; lasing; monolithic VCSELs; multiple active regions; signal to noise ratio; single optical waveguide; source stability; technologically important wavelength; three-stage active region; Contact resistance; Laser modes; Laser noise; Masers; Optical losses; Optical waveguides; Signal to noise ratio; Stacking; Threshold current; Vertical cavity surface emitting lasers;
Conference_Titel :
Nanostructures and Quantum Dots/WDM Components/VCSELs and Microcavaties/RF Photonics for CATV and HFC Systems, 1999 Digest of the LEOS Summer Topical Meetings
Conference_Location :
San Diego, CA, USA
Print_ISBN :
0-7803-5633-0
DOI :
10.1109/LEOSST.1999.794707