| About this Abstract |
| Meeting |
2011 Electronic Materials Conference
|
| Symposium
|
2011 Electronic Materials Conference
|
| Presentation Title |
F1, Design and Growth of InAs Quantum Dash Based MWIR VECSELs |
| Author(s) |
Victor Patel, Simon Reissmann, Thomas J. Rotter, Pankaj Ahirwar, Stephen P. R. Clark, Alexander R. Albrecht, Huiwen Xu, Christopher P. Hains, Larry Ralph Dawson, Ganesh Balakrishnan |
| On-Site Speaker (Planned) |
Victor Patel |
| Abstract Scope |
Antimonide Quantum Well (QW) based active regions currently dominate MWIR Vertical External Cavity Surface Emitting Lasers (VECSELs). The lack of etch stop layers in the antimonide material system (6.1 Å family) has made the fabrication of high power lasers rather difficult, since the high-power results depend on effective substrate removal techniques. The InAs Quantum Dash (QDash) based VECSEL can become an effective alternative to the antimonides due to the presence of very mature etch stop layers in the InP material system. QDash active regions exhibit broader gain bandwidth compared to QWs and therefore can result in superior tunability and mode locking. Furthermore, the QDash’s highly coherent strain can help suppress the Auger non-radiative recombination and lead to more efficient MWIR lasers. The InAs nanostructures grown on lattice matched (Al<SUB>x</SUB>Ga<SUB>1-x</SUB>)<SUB>0.47</SUB>In<SUB>0.53</SUB>As buffers on InP substrates form asymmetric structures called Quantum Dashes in the Stranski Krastanov growth mode due to the 3.2% compressive strain with respect to InP. The three dimensional structures provide a way to release the compressive strain by elastic strain relaxation. Since the structures are free of dislocations, QDashes exhibit good optical properties. The Dashes are elongated in the [1-10] direction. Since InAs/InP are less mismatched alloys compared to InAs/GaAs they are capable of being grown with more InAs coverage, which results in emission wavelength covering 1.5 to 2.1 μm. The QDash based active regions have been used to realize 2 μm edge-emitting lasers. In this presentation we shall discuss the design and growth of a 2 μm InAs Quantum Dash VECSELs. This is grown as a bottom-emitting structure where the active region is grown on an InP substrate and the distributed Bragg Reflector (DBR) is grown on top. QDashes are incorporated in a 1% compressively strained quantum well to form a dashes-in-well (DWELL) based active region. The DWELL structure improves the carrier capture efficiency. Carriers that are captured in the QWs have a greater probability of being captured by the QDashes. A metamorphic AlSb/GaSb DBRs is utilized; this offers a better index contrast compared to lattice matched ternaries on InP. The chip is then mounted such that the DBR is bonded to a CVD diamond chip and the InP substrate is etched off. |
| Proceedings Inclusion? |
Undecided |